Remove unused variables

41 files changed, 76 insertions, 143 deletions

diff --git a/ffmpeg.c b/ffmpeg.c
index 7721438ad1..15ac03e3ed 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -1117,7 +1117,7 @@ static void do_video_out(AVFormatContext *s,
                          int *frame_size)
 {
     int nb_frames, i, ret, resample_changed;
-    AVFrame *final_picture, *formatted_picture, *resampling_dst;
+    AVFrame *final_picture, *formatted_picture;
     AVCodecContext *enc, *dec;
     double sync_ipts;
 
@@ -1162,7 +1162,6 @@ static void do_video_out(AVFormatContext *s,
 
     formatted_picture = in_picture;
     final_picture = formatted_picture;
-    resampling_dst = &ost->pict_tmp;
 
     resample_changed = ost->resample_width   != dec->width  ||
                        ost->resample_height  != dec->height ||
@@ -1198,7 +1197,7 @@ static void do_video_out(AVFormatContext *s,
             }
         }
         sws_scale(ost->img_resample_ctx, formatted_picture->data, formatted_picture->linesize,
-              0, ost->resample_height, resampling_dst->data, resampling_dst->linesize);
+              0, ost->resample_height, final_picture->data, final_picture->linesize);
     }
 #endif
 
@@ -3617,7 +3616,6 @@ static void new_audio_stream(AVFormatContext *oc, int file_idx)
 static void new_data_stream(AVFormatContext *oc, int file_idx)
 {
     AVStream *st;
-    AVOutputStream *ost;
     AVCodec *codec=NULL;
     AVCodecContext *data_enc;
 
@@ -3626,7 +3624,7 @@ static void new_data_stream(AVFormatContext *oc, int file_idx)
         fprintf(stderr, "Could not alloc stream\n");
         ffmpeg_exit(1);
     }
-    ost = new_output_stream(oc, file_idx);
+    new_output_stream(oc, file_idx);
     data_enc = st->codec;
     output_codecs = grow_array(output_codecs, sizeof(*output_codecs), &nb_output_codecs, nb_output_codecs + 1);
     if (!data_stream_copy) {
diff --git a/libavcodec/a64multienc.c b/libavcodec/a64multienc.c
index 8286d7ee3c..532f2a2824 100644
--- a/libavcodec/a64multienc.c
+++ b/libavcodec/a64multienc.c
@@ -252,7 +252,6 @@ static int a64multi_encode_frame(AVCodecContext *avctx, unsigned char *buf,
     int b_width;
 
     int req_size;
-    int num_frames   = c->mc_lifetime;
 
     int *charmap     = c->mc_charmap;
     uint8_t *colram  = c->mc_colram;
@@ -280,7 +279,6 @@ static int a64multi_encode_frame(AVCodecContext *avctx, unsigned char *buf,
         if (!c->mc_lifetime) return 0;
         /* no more frames in queue, prepare to flush remaining frames */
         if (!c->mc_frame_counter) {
-            num_frames = c->mc_lifetime;
             c->mc_lifetime = 0;
         }
         /* still frames in queue so limit lifetime to remaining frames */
diff --git a/libavcodec/aaccoder.c b/libavcodec/aaccoder.c
index 83d3734089..4d5b98fa63 100644
--- a/libavcodec/aaccoder.c
+++ b/libavcodec/aaccoder.c
@@ -311,7 +311,7 @@ static void encode_window_bands_info(AACEncContext *s, SingleChannelElement *sce
                                      int win, int group_len, const float lambda)
 {
     BandCodingPath path[120][12];
-    int w, swb, cb, start, start2, size;
+    int w, swb, cb, start, size;
     int i, j;
     const int max_sfb  = sce->ics.max_sfb;
     const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
@@ -329,7 +329,6 @@ static void encode_window_bands_info(AACEncContext *s, SingleChannelElement *sce
         path[0][cb].run      = 0;
     }
     for (swb = 0; swb < max_sfb; swb++) {
-        start2 = start;
         size = sce->ics.swb_sizes[swb];
         if (sce->zeroes[win*16 + swb]) {
             for (cb = 0; cb < 12; cb++) {
@@ -413,7 +412,7 @@ static void codebook_trellis_rate(AACEncContext *s, SingleChannelElement *sce,
                                   int win, int group_len, const float lambda)
 {
     BandCodingPath path[120][12];
-    int w, swb, cb, start, start2, size;
+    int w, swb, cb, start, size;
     int i, j;
     const int max_sfb  = sce->ics.max_sfb;
     const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
@@ -431,7 +430,6 @@ static void codebook_trellis_rate(AACEncContext *s, SingleChannelElement *sce,
         path[0][cb].run      = 0;
     }
     for (swb = 0; swb < max_sfb; swb++) {
-        start2 = start;
         size = sce->ics.swb_sizes[swb];
         if (sce->zeroes[win*16 + swb]) {
             for (cb = 0; cb < 12; cb++) {
@@ -1006,12 +1004,11 @@ static void search_for_quantizers_fast(AVCodecContext *avctx, AACEncContext *s,
                                        SingleChannelElement *sce,
                                        const float lambda)
 {
-    int start = 0, i, w, w2, g;
+    int i, w, w2, g;
     int minq = 255;
 
     memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
-        start = w*128;
         for (g = 0; g < sce->ics.num_swb; g++) {
             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                 FFPsyBand *band = &s->psy.psy_bands[s->cur_channel*PSY_MAX_BANDS+(w+w2)*16+g];
diff --git a/libavcodec/celp_filters.c b/libavcodec/celp_filters.c
index 32eaff3c75..25a6744b04 100644
--- a/libavcodec/celp_filters.c
+++ b/libavcodec/celp_filters.c
@@ -109,7 +109,7 @@ void ff_celp_lp_synthesis_filterf(float *out, const float *filter_coeffs,
     old_out2 = out[-2];
     old_out3 = out[-1];
     for (n = 0; n <= buffer_length - 4; n+=4) {
-        float tmp0,tmp1,tmp2,tmp3;
+        float tmp0,tmp1,tmp2;
         float val;
 
         out0 = in[0];
@@ -160,7 +160,6 @@ void ff_celp_lp_synthesis_filterf(float *out, const float *filter_coeffs,
         tmp0 = out0;
         tmp1 = out1;
         tmp2 = out2;
-        tmp3 = out3;
 
         out3 -= a * tmp2;
         out2 -= a * tmp1;
diff --git a/libavcodec/dca.c b/libavcodec/dca.c
index dbadebacff..a9b2c9b0c9 100644
--- a/libavcodec/dca.c
+++ b/libavcodec/dca.c
@@ -1535,8 +1535,6 @@ static void dca_exss_parse_header(DCAContext *s)
 {
     int ss_index;
     int blownup;
-    int header_size;
-    int hd_size;
     int num_audiop = 1;
     int num_assets = 1;
     int active_ss_mask[8];
@@ -1549,8 +1547,8 @@ static void dca_exss_parse_header(DCAContext *s)
     ss_index = get_bits(&s->gb, 2);
 
     blownup = get_bits1(&s->gb);
-    header_size = get_bits(&s->gb, 8 + 4 * blownup) + 1;
-    hd_size = get_bits_long(&s->gb, 16 + 4 * blownup) + 1;
+    skip_bits(&s->gb, 8 + 4 * blownup); // header_size
+    skip_bits(&s->gb, 16 + 4 * blownup); // hd_size
 
     s->static_fields = get_bits1(&s->gb);
     if (s->static_fields) {
diff --git a/libavcodec/dirac.c b/libavcodec/dirac.c
index 0256f29a53..09da1cbd56 100644
--- a/libavcodec/dirac.c
+++ b/libavcodec/dirac.c
@@ -245,11 +245,11 @@ static int parse_source_parameters(AVCodecContext *avctx, GetBitContext *gb,
 int ff_dirac_parse_sequence_header(AVCodecContext *avctx, GetBitContext *gb,
                                    dirac_source_params *source)
 {
-    unsigned version_major, version_minor;
+    unsigned version_major;
     unsigned video_format, picture_coding_mode;
 
     version_major  = svq3_get_ue_golomb(gb);
-    version_minor  = svq3_get_ue_golomb(gb);
+    svq3_get_ue_golomb(gb); /* version_minor */
     avctx->profile = svq3_get_ue_golomb(gb);
     avctx->level   = svq3_get_ue_golomb(gb);
     video_format   = svq3_get_ue_golomb(gb);
diff --git a/libavcodec/ituh263dec.c b/libavcodec/ituh263dec.c
index aebfcee027..0bb92da833 100644
--- a/libavcodec/ituh263dec.c
+++ b/libavcodec/ituh263dec.c
@@ -152,7 +152,7 @@ int ff_h263_decode_mba(MpegEncContext *s)
  */
 static int h263_decode_gob_header(MpegEncContext *s)
 {
-    unsigned int val, gfid, gob_number;
+    unsigned int val, gob_number;
     int left;
 
     /* Check for GOB Start Code */
@@ -183,12 +183,12 @@ static int h263_decode_gob_header(MpegEncContext *s)
         s->qscale = get_bits(&s->gb, 5); /* SQUANT */
         if(get_bits1(&s->gb)==0)
             return -1;
-        gfid = get_bits(&s->gb, 2); /* GFID */
+        skip_bits(&s->gb, 2); /* GFID */
     }else{
         gob_number = get_bits(&s->gb, 5); /* GN */
         s->mb_x= 0;
         s->mb_y= s->gob_index* gob_number;
-        gfid = get_bits(&s->gb, 2); /* GFID */
+        skip_bits(&s->gb, 2); /* GFID */
         s->qscale = get_bits(&s->gb, 5); /* GQUANT */
     }
 
diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
index 82c2987b90..0e1536f7ab 100644
--- a/libavcodec/mpeg12.c
+++ b/libavcodec/mpeg12.c
@@ -2128,14 +2128,13 @@ static void mpeg_decode_gop(AVCodecContext *avctx,
     Mpeg1Context *s1 = avctx->priv_data;
     MpegEncContext *s = &s1->mpeg_enc_ctx;
 
-    int drop_frame_flag;
     int time_code_hours, time_code_minutes;
     int time_code_seconds, time_code_pictures;
     int broken_link;
 
     init_get_bits(&s->gb, buf, buf_size*8);
 
-    drop_frame_flag = get_bits1(&s->gb);
+    skip_bits1(&s->gb); /* drop_frame_flag */
 
     time_code_hours=get_bits(&s->gb,5);
     time_code_minutes = get_bits(&s->gb,6);
diff --git a/libavcodec/mpeg12enc.c b/libavcodec/mpeg12enc.c
index 8aa31f7581..eb07ecfc5e 100644
--- a/libavcodec/mpeg12enc.c
+++ b/libavcodec/mpeg12enc.c
@@ -761,10 +761,9 @@ void ff_mpeg1_encode_init(MpegEncContext *s)
 
                 if(mv==0) len= ff_mpeg12_mbMotionVectorTable[0][1];
                 else{
-                    int val, bit_size, range, code;
+                    int val, bit_size, code;
 
                     bit_size = f_code - 1;
-                    range = 1 << bit_size;
 
                     val=mv;
                     if (val < 0)
diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
index 81f09c5a4b..22d7ace789 100644
--- a/libavcodec/mpeg4videodec.c
+++ b/libavcodec/mpeg4videodec.c
@@ -397,14 +397,13 @@ int mpeg4_decode_video_packet_header(MpegEncContext *s)
         header_extension= get_bits1(&s->gb);
     }
     if(header_extension){
-        int time_increment;
         int time_incr=0;
 
         while (get_bits1(&s->gb) != 0)
             time_incr++;
 
         check_marker(&s->gb, "before time_increment in video packed header");
-        time_increment= get_bits(&s->gb, s->time_increment_bits);
+        skip_bits(&s->gb, s->time_increment_bits); /* time_increment */
         check_marker(&s->gb, "before vop_coding_type in video packed header");
 
         skip_bits(&s->gb, 2); /* vop coding type */
@@ -1801,16 +1800,14 @@ no_cplx_est:
 
         if (s->scalability) {
             GetBitContext bak= *gb;
-            int ref_layer_id;
-            int ref_layer_sampling_dir;
             int h_sampling_factor_n;
             int h_sampling_factor_m;
             int v_sampling_factor_n;
             int v_sampling_factor_m;
 
             s->hierachy_type= get_bits1(gb);
-            ref_layer_id= get_bits(gb, 4);
-            ref_layer_sampling_dir= get_bits1(gb);
+            skip_bits(gb, 4);  /* ref_layer_id */
+            skip_bits1(gb);    /* ref_layer_sampling_dir */
             h_sampling_factor_n= get_bits(gb, 5);
             h_sampling_factor_m= get_bits(gb, 5);
             v_sampling_factor_n= get_bits(gb, 5);
@@ -1989,15 +1986,13 @@ static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
 
      if (s->shape != RECT_SHAPE) {
          if (s->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
-             int width, height, hor_spat_ref, ver_spat_ref;
-
-             width = get_bits(gb, 13);
+             skip_bits(gb, 13); /* width */
              skip_bits1(gb);   /* marker */
-             height = get_bits(gb, 13);
+             skip_bits(gb, 13); /* height */
              skip_bits1(gb);   /* marker */
-             hor_spat_ref = get_bits(gb, 13); /* hor_spat_ref */
+             skip_bits(gb, 13); /* hor_spat_ref */
              skip_bits1(gb);   /* marker */
-             ver_spat_ref = get_bits(gb, 13); /* ver_spat_ref */
+             skip_bits(gb, 13); /* ver_spat_ref */
          }
          skip_bits1(gb); /* change_CR_disable */
 
diff --git a/libavcodec/mpegvideo_parser.c b/libavcodec/mpegvideo_parser.c
index 42c85874f6..9688e18625 100644
--- a/libavcodec/mpegvideo_parser.c
+++ b/libavcodec/mpegvideo_parser.c
@@ -32,7 +32,7 @@ static void mpegvideo_extract_headers(AVCodecParserContext *s,
     uint32_t start_code;
     int frame_rate_index, ext_type, bytes_left;
     int frame_rate_ext_n, frame_rate_ext_d;
-    int picture_structure, top_field_first, repeat_first_field, progressive_frame;
+    int top_field_first, repeat_first_field, progressive_frame;
     int horiz_size_ext, vert_size_ext, bit_rate_ext;
     int did_set_size=0;
 //FIXME replace the crap with get_bits()
@@ -91,7 +91,6 @@ static void mpegvideo_extract_headers(AVCodecParserContext *s,
                     break;
                 case 0x8: /* picture coding extension */
                     if (bytes_left >= 5) {
-                        picture_structure = buf[2]&3;
                         top_field_first = buf[3] & (1 << 7);
                         repeat_first_field = buf[3] & (1 << 1);
                         progressive_frame = buf[4] & (1 << 7);
diff --git a/libavcodec/msmpeg4.c b/libavcodec/msmpeg4.c
index c575a2f206..c740cfa0bd 100644
--- a/libavcodec/msmpeg4.c
+++ b/libavcodec/msmpeg4.c
@@ -1528,9 +1528,7 @@ int msmpeg4_decode_ext_header(MpegEncContext * s, int buf_size)
     /* the alt_bitstream reader could read over the end so we need to check it */
     if(left>=length && left<length+8)
     {
-        int fps;
-
-        fps= get_bits(&s->gb, 5);
+        skip_bits(&s->gb, 5); /* fps */
         s->bit_rate= get_bits(&s->gb, 11)*1024;
         if(s->msmpeg4_version>=3)
             s->flipflop_rounding= get_bits1(&s->gb);
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 39dbfdcc6f..7477f6746b 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -397,7 +397,7 @@ static int decode_frame(AVCodecContext *avctx,
     AVFrame *p;
     uint8_t *crow_buf_base = NULL;
     uint32_t tag, length;
-    int ret, crc;
+    int ret;
 
     FFSWAP(AVFrame *, s->current_picture, s->last_picture);
     avctx->coded_frame= s->current_picture;
@@ -451,7 +451,7 @@ static int decode_frame(AVCodecContext *avctx,
             s->compression_type = *s->bytestream++;
             s->filter_type = *s->bytestream++;
             s->interlace_type = *s->bytestream++;
-            crc = bytestream_get_be32(&s->bytestream);
+            s->bytestream += 4; /* crc */
             s->state |= PNG_IHDR;
             av_dlog(avctx, "width=%d height=%d depth=%d color_type=%d compression_type=%d filter_type=%d interlace_type=%d\n",
                     s->width, s->height, s->bit_depth, s->color_type,
@@ -547,8 +547,7 @@ static int decode_frame(AVCodecContext *avctx,
             s->state |= PNG_IDAT;
             if (png_decode_idat(s, length) < 0)
                 goto fail;
-            /* skip crc */
-            crc = bytestream_get_be32(&s->bytestream);
+            s->bytestream += 4; /* crc */
             break;
         case MKTAG('P', 'L', 'T', 'E'):
             {
@@ -568,7 +567,7 @@ static int decode_frame(AVCodecContext *avctx,
                     s->palette[i] = (0xff << 24);
                 }
                 s->state |= PNG_PLTE;
-                crc = bytestream_get_be32(&s->bytestream);
+                s->bytestream += 4; /* crc */
             }
             break;
         case MKTAG('t', 'R', 'N', 'S'):
@@ -584,13 +583,13 @@ static int decode_frame(AVCodecContext *avctx,
                     v = *s->bytestream++;
                     s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
                 }
-                crc = bytestream_get_be32(&s->bytestream);
+                s->bytestream += 4; /* crc */
             }
             break;
         case MKTAG('I', 'E', 'N', 'D'):
             if (!(s->state & PNG_ALLIMAGE))
                 goto fail;
-            crc = bytestream_get_be32(&s->bytestream);
+            s->bytestream += 4; /* crc */
             goto exit_loop;
         default:
             /* skip tag */
diff --git a/libavcodec/rv10.c b/libavcodec/rv10.c
index d85cf37cac..6227dc6f6c 100644
--- a/libavcodec/rv10.c
+++ b/libavcodec/rv10.c
@@ -235,7 +235,7 @@ int rv_decode_dc(MpegEncContext *s, int n)
 /* read RV 1.0 compatible frame header */
 static int rv10_decode_picture_header(MpegEncContext *s)
 {
-    int mb_count, pb_frame, marker, unk, mb_xy;
+    int mb_count, pb_frame, marker, mb_xy;
 
     marker = get_bits1(&s->gb);
 
@@ -282,7 +282,7 @@ static int rv10_decode_picture_header(MpegEncContext *s)
         s->mb_y = 0;
         mb_count = s->mb_width * s->mb_height;
     }
-    unk= get_bits(&s->gb, 3);   /* ignored */
+    skip_bits(&s->gb, 3);   /* ignored */
     s->f_code = 1;
     s->unrestricted_mv = 1;
 
diff --git a/libavcodec/s302m.c b/libavcodec/s302m.c
index fb1fd867d0..9d623efa8f 100644
--- a/libavcodec/s302m.c
+++ b/libavcodec/s302m.c
@@ -29,7 +29,7 @@ static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf,
                                     int buf_size)
 {
     uint32_t h;
-    int frame_size, channels, id, bits;
+    int frame_size, channels, bits;
 
     if (buf_size <= AES3_HEADER_LEN) {
         av_log(avctx, AV_LOG_ERROR, "frame is too short\n");
@@ -48,7 +48,6 @@ static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf,
     h = AV_RB32(buf);
     frame_size =  (h >> 16) & 0xffff;
     channels   = ((h >> 14) & 0x0003) * 2 +  2;
-    id         =  (h >>  6) & 0x00ff;
     bits       = ((h >>  4) & 0x0003) * 4 + 16;
 
     if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) {
diff --git a/libavcodec/shorten.c b/libavcodec/shorten.c
index f19f0fe348..86e981f417 100644
--- a/libavcodec/shorten.c
+++ b/libavcodec/shorten.c
@@ -196,7 +196,6 @@ static int decode_wave_header(AVCodecContext *avctx, uint8_t *header, int header
 {
     GetBitContext hb;
     int len;
-    int chunk_size;
     short wave_format;
 
     init_get_bits(&hb, header, header_size*8);
@@ -205,7 +204,7 @@ static int decode_wave_header(AVCodecContext *avctx, uint8_t *header, int header
         return -1;
     }
 
-    chunk_size = get_le32(&hb);
+    skip_bits_long(&hb, 32);    /* chunk_size */
 
     if (get_le32(&hb) != MKTAG('W','A','V','E')) {
         av_log(avctx, AV_LOG_ERROR, "missing WAVE tag\n");
diff --git a/libavcodec/sp5xdec.c b/libavcodec/sp5xdec.c
index 3d01020a6d..6726c18ca9 100644
--- a/libavcodec/sp5xdec.c
+++ b/libavcodec/sp5xdec.c
@@ -38,15 +38,12 @@ static int sp5x_decode_frame(AVCodecContext *avctx,
     int buf_size = avpkt->size;
     AVPacket avpkt_recoded;
     const int qscale = 5;
-    const uint8_t *buf_ptr;
     uint8_t *recoded;
     int i = 0, j = 0;
 
     if (!avctx->width || !avctx->height)
         return -1;
 
-    buf_ptr = buf;
-
     recoded = av_mallocz(buf_size + 1024);
     if (!recoded)
         return -1;
diff --git a/libavcodec/svq1dec.c b/libavcodec/svq1dec.c
index 0ab09298fc..ef3b4be16c 100644
--- a/libavcodec/svq1dec.c
+++ b/libavcodec/svq1dec.c
@@ -554,9 +554,8 @@ static void svq1_parse_string (GetBitContext *bitbuf, uint8_t *out) {
 
 static int svq1_decode_frame_header (GetBitContext *bitbuf,MpegEncContext *s) {
   int frame_size_code;
-  int temporal_reference;
 
-  temporal_reference = get_bits (bitbuf, 8);
+  skip_bits(bitbuf, 8); /* temporal_reference */
 
   /* frame type */
   s->pict_type= get_bits (bitbuf, 2)+1;
diff --git a/libavcodec/targa.c b/libavcodec/targa.c
index 910cc1ba94..6a852a8528 100644
--- a/libavcodec/targa.c
+++ b/libavcodec/targa.c
@@ -108,18 +108,18 @@ static int decode_frame(AVCodecContext *avctx,
     AVFrame * const p= (AVFrame*)&s->picture;
     uint8_t *dst;
     int stride;
-    int idlen, pal, compr, x, y, w, h, bpp, flags;
+    int idlen, compr, y, w, h, bpp, flags;
     int first_clr, colors, csize;
 
     /* parse image header */
     CHECK_BUFFER_SIZE(buf, buf_end, 18, "header");
     idlen = *buf++;
-    pal = *buf++;
+    buf++; /* pal */
     compr = *buf++;
     first_clr = AV_RL16(buf); buf += 2;
     colors = AV_RL16(buf); buf += 2;
     csize = *buf++;
-    x = AV_RL16(buf); buf += 2;
+    buf += 2; /* x */
     y = AV_RL16(buf); buf += 2;
     w = AV_RL16(buf); buf += 2;
     h = AV_RL16(buf); buf += 2;
diff --git a/libavcodec/truemotion2.c b/libavcodec/truemotion2.c
index f9e607c4f7..23abade214 100644
--- a/libavcodec/truemotion2.c
+++ b/libavcodec/truemotion2.c
@@ -201,7 +201,6 @@ static inline int tm2_read_header(TM2Context *ctx, const uint8_t *buf)
 {
     uint32_t magic;
     const uint8_t *obuf;
-    int length;
 
     obuf = buf;
 
@@ -212,19 +211,6 @@ static inline int tm2_read_header(TM2Context *ctx, const uint8_t *buf)
 /*      av_log (ctx->avctx, AV_LOG_ERROR, "TM2 old header: not implemented (yet)\n"); */
         return 40;
     } else if(magic == 0x00000101) { /* new header */
-        int w, h, size, flags, xr, yr;
-
-        length = AV_RL32(buf);
-        buf += 4;
-
-        init_get_bits(&ctx->gb, buf, 32 * 8);
-        size = get_bits_long(&ctx->gb, 31);
-        h = get_bits(&ctx->gb, 15);
-        w = get_bits(&ctx->gb, 15);
-        flags = get_bits_long(&ctx->gb, 31);
-        yr = get_bits(&ctx->gb, 9);
-        xr = get_bits(&ctx->gb, 9);
-
         return 40;
     } else {
         av_log (ctx->avctx, AV_LOG_ERROR, "Not a TM2 header: 0x%08X\n", magic);
diff --git a/libavcodec/tscc.c b/libavcodec/tscc.c
index bd05f02a61..772906aba6 100644
--- a/libavcodec/tscc.c
+++ b/libavcodec/tscc.c
@@ -75,7 +75,6 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPac
     int buf_size = avpkt->size;
     CamtasiaContext * const c = avctx->priv_data;
     const unsigned char *encoded = buf;
-    unsigned char *outptr;
     int zret; // Zlib return code
     int len = buf_size;
 
@@ -89,8 +88,6 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPac
         return -1;
     }
 
-    outptr = c->pic.data[0]; // Output image pointer
-
     zret = inflateReset(&(c->zstream));
     if (zret != Z_OK) {
         av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
diff --git a/libavcodec/vmdav.c b/libavcodec/vmdav.c
index 710c2028cf..d258252d95 100644
--- a/libavcodec/vmdav.c
+++ b/libavcodec/vmdav.c
@@ -199,7 +199,6 @@ static void vmd_decode(VmdVideoContext *s)
 
     int frame_x, frame_y;
     int frame_width, frame_height;
-    int dp_size;
 
     frame_x = AV_RL16(&s->buf[6]);
     frame_y = AV_RL16(&s->buf[8]);
@@ -247,7 +246,6 @@ static void vmd_decode(VmdVideoContext *s)
         }
 
         dp = &s->frame.data[0][frame_y * s->frame.linesize[0] + frame_x];
-        dp_size = s->frame.linesize[0] * s->avctx->height;
         pp = &s->prev_frame.data[0][frame_y * s->prev_frame.linesize[0] + frame_x];
         switch (meth) {
         case 1:
diff --git a/libavcodec/zmbvenc.c b/libavcodec/zmbvenc.c
index 271ab2dc96..e4f4860ea0 100644
--- a/libavcodec/zmbvenc.c
+++ b/libavcodec/zmbvenc.c
@@ -181,7 +181,7 @@ static int encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void
         int x, y, bh2, bw2, xored;
         uint8_t *tsrc, *tprev;
         uint8_t *mv;
-        int mx, my, bv;
+        int mx, my;
 
         bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
         bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
@@ -197,7 +197,7 @@ static int encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void
                 tsrc = src + x;
                 tprev = prev + x;
 
-                bv = zmbv_me(c, tsrc, p->linesize[0], tprev, c->pstride, x, y, &mx, &my, &xored);
+                zmbv_me(c, tsrc, p->linesize[0], tprev, c->pstride, x, y, &mx, &my, &xored);
                 mv[0] = (mx << 1) | !!xored;
                 mv[1] = my << 1;
                 tprev += mx + my * c->pstride;
diff --git a/libavfilter/vf_fieldorder.c b/libavfilter/vf_fieldorder.c
index b55640bbc2..444dffb52c 100644
--- a/libavfilter/vf_fieldorder.c
+++ b/libavfilter/vf_fieldorder.c
@@ -153,7 +153,7 @@ static void end_frame(AVFilterLink *inlink)
     AVFilterBufferRef *inpicref   = inlink->cur_buf;
     AVFilterBufferRef *outpicref  = outlink->out_buf;
 
-    int               h, w, plane, line_step, line_size, line;
+    int               h, plane, line_step, line_size, line;
     uint8_t           *cpy_src, *cpy_dst;
 
     if (    inpicref->video->interlaced
@@ -162,7 +162,6 @@ static void end_frame(AVFilterLink *inlink)
                 "picture will move %s one line\n",
                 fieldorder->dst_tff ? "up" : "down");
         h = inpicref->video->h;
-        w = inpicref->video->w;
         for (plane = 0; plane < 4 && inpicref->data[plane]; plane++) {
             line_step = inpicref->linesize[plane];
             line_size = fieldorder->line_size[plane];
diff --git a/libavformat/4xm.c b/libavformat/4xm.c
index ff0baaec8f..93c90e8cbc 100644
--- a/libavformat/4xm.c
+++ b/libavformat/4xm.c
@@ -246,7 +246,7 @@ static int fourxm_read_packet(AVFormatContext *s,
     FourxmDemuxContext *fourxm = s->priv_data;
     AVIOContext *pb = s->pb;
     unsigned int fourcc_tag;
-    unsigned int size, out_size;
+    unsigned int size;
     int ret = 0;
     unsigned int track_number;
     int packet_read = 0;
@@ -295,7 +295,7 @@ static int fourxm_read_packet(AVFormatContext *s,
 
         case snd__TAG:
             track_number = avio_rl32(pb);
-            out_size= avio_rl32(pb);
+            avio_skip(pb, 4);
             size-=8;
 
             if (track_number < fourxm->track_count && fourxm->tracks[track_number].channels>0) {
diff --git a/libavformat/apetag.c b/libavformat/apetag.c
index b8a460a599..6e925354af 100644
--- a/libavformat/apetag.c
+++ b/libavformat/apetag.c
@@ -35,11 +35,11 @@ static int ape_tag_read_field(AVFormatContext *s)
 {
     AVIOContext *pb = s->pb;
     uint8_t key[1024], *value;
-    uint32_t size, flags;
+    uint32_t size;
     int i, c;
 
     size = avio_rl32(pb);  /* field size */
-    flags = avio_rl32(pb); /* field flags */
+    avio_skip(pb, 4);      /* field flags */
     for (i = 0; i < sizeof(key) - 1; i++) {
         c = avio_r8(pb);
         if (c < 0x20 || c > 0x7E)
diff --git a/libavformat/asfdec.c b/libavformat/asfdec.c
index 30642a61fa..789df1274d 100644
--- a/libavformat/asfdec.c
+++ b/libavformat/asfdec.c
@@ -216,7 +216,6 @@ static int asf_read_stream_properties(AVFormatContext *s, int64_t size)
     ff_asf_guid g;
     enum AVMediaType type;
     int type_specific_size, sizeX;
-    uint64_t total_size;
     unsigned int tag1;
     int64_t pos1, pos2, start_time;
     int test_for_ext_stream_audio, is_dvr_ms_audio=0;
@@ -264,7 +263,7 @@ static int asf_read_stream_properties(AVFormatContext *s, int64_t size)
         return -1;
     }
     ff_get_guid(pb, &g);
-    total_size = avio_rl64(pb);
+    avio_skip(pb, 8); /* total_size */
     type_specific_size = avio_rl32(pb);
     avio_rl32(pb);
     st->id = avio_rl16(pb) & 0x7f; /* stream id */
@@ -401,7 +400,7 @@ static int asf_read_ext_stream_properties(AVFormatContext *s, int64_t size)
     AVIOContext *pb = s->pb;
     ff_asf_guid g;
     int ext_len, payload_ext_ct, stream_ct, i;
-    uint32_t ext_d, leak_rate, stream_num;
+    uint32_t leak_rate, stream_num;
     unsigned int stream_languageid_index;
 
     avio_rl64(pb); // starttime
@@ -435,7 +434,7 @@ static int asf_read_ext_stream_properties(AVFormatContext *s, int64_t size)
 
     for (i=0; i<payload_ext_ct; i++){
         ff_get_guid(pb, &g);
-        ext_d=avio_rl16(pb);
+        avio_skip(pb, 2);
         ext_len=avio_rl32(pb);
         avio_skip(pb, ext_len);
     }
@@ -519,7 +518,7 @@ static int asf_read_metadata(AVFormatContext *s, int64_t size)
 {
     AVIOContext *pb = s->pb;
     ASFContext *asf = s->priv_data;
-    int n, stream_num, name_len, value_len, value_type, value_num;
+    int n, stream_num, name_len, value_len, value_num;
     int ret, i;
     n = avio_rl16(pb);
 
@@ -529,7 +528,7 @@ static int asf_read_metadata(AVFormatContext *s, int64_t size)
         avio_rl16(pb); //lang_list_index
         stream_num= avio_rl16(pb);
         name_len=   avio_rl16(pb);
-        value_type= avio_rl16(pb);
+        avio_skip(pb, 2); /* value_type */
         value_len=  avio_rl32(pb);
 
         if ((ret = avio_get_str16le(pb, name_len, name, sizeof(name))) < name_len)
@@ -634,10 +633,8 @@ static int asf_read_header(AVFormatContext *s, AVFormatParameters *ap)
             // if so the next iteration will pick it up
             continue;
         } else if (!ff_guidcmp(&g, &ff_asf_head1_guid)) {
-            int v1, v2;
             ff_get_guid(pb, &g);
-            v1 = avio_rl32(pb);
-            v2 = avio_rl16(pb);
+            avio_skip(pb, 6);
             continue;
         } else if (!ff_guidcmp(&g, &ff_asf_marker_header)) {
             asf_read_marker(s, gsize);
@@ -807,7 +804,7 @@ static int asf_read_frame_header(AVFormatContext *s, AVIOContext *pb){
     ASFContext *asf = s->priv_data;
     int rsize = 1;
     int num = avio_r8(pb);
-    int64_t ts0, ts1;
+    int64_t ts0;
 
     asf->packet_segments--;
     asf->packet_key_frame = num >> 7;
@@ -830,7 +827,7 @@ static int asf_read_frame_header(AVFormatContext *s, AVIOContext *pb){
 //            av_log(s, AV_LOG_DEBUG, "\n");
             avio_skip(pb, 10);
             ts0= avio_rl64(pb);
-            ts1= avio_rl64(pb);
+            avio_skip(pb, 8);;
             avio_skip(pb, 12);
             avio_rl32(pb);
             avio_skip(pb, asf->packet_replic_size - 8 - 38 - 4);
diff --git a/libavformat/avidec.c b/libavformat/avidec.c
index a9ff688a86..ff270edae5 100644
--- a/libavformat/avidec.c
+++ b/libavformat/avidec.c
@@ -337,7 +337,7 @@ static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
     AVIContext *avi = s->priv_data;
     AVIOContext *pb = s->pb;
     unsigned int tag, tag1, handler;
-    int codec_type, stream_index, frame_period, bit_rate;
+    int codec_type, stream_index, frame_period;
     unsigned int size;
     int i;
     AVStream *st;
@@ -407,7 +407,7 @@ static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
             /* AVI header */
             /* using frame_period is bad idea */
             frame_period = avio_rl32(pb);
-            bit_rate = avio_rl32(pb) * 8;
+            avio_skip(pb, 4);
             avio_rl32(pb);
             avi->non_interleaved |= avio_rl32(pb) & AVIF_MUSTUSEINDEX;
 
diff --git a/libavformat/gif.c b/libavformat/gif.c
index dfd2ec16e8..55deb4d207 100644
--- a/libavformat/gif.c
+++ b/libavformat/gif.c
@@ -295,9 +295,7 @@ static int gif_write_video(AVFormatContext *s,
                            AVCodecContext *enc, const uint8_t *buf, int size)
 {
     AVIOContext *pb = s->pb;
-    GIFContext *gif = s->priv_data;
     int jiffies;
-    int64_t delay;
 
     /* graphic control extension block */
     avio_w8(pb, 0x21);
@@ -307,8 +305,6 @@ static int gif_write_video(AVFormatContext *s,
 
     /* 1 jiffy is 1/70 s */
     /* the delay_time field indicates the number of jiffies - 1 */
-    delay = gif->file_time - gif->time;
-
     /* XXX: should use delay, in order to be more accurate */
     /* instead of using the same rounded value each time */
     /* XXX: don't even remember if I really use it for now */
diff --git a/libavformat/mmf.c b/libavformat/mmf.c
index ec99c2d0dd..3848d5cf56 100644
--- a/libavformat/mmf.c
+++ b/libavformat/mmf.c
@@ -186,13 +186,13 @@ static int mmf_read_header(AVFormatContext *s,
     unsigned int tag;
     AVIOContext *pb = s->pb;
     AVStream *st;
-    int64_t file_size, size;
+    int64_t size;
     int rate, params;
 
     tag = avio_rl32(pb);
     if (tag != MKTAG('M', 'M', 'M', 'D'))
         return -1;
-    file_size = avio_rb32(pb);
+    avio_skip(pb, 4); /* file_size */
 
     /* Skip some unused chunks that may or may not be present */
     for(;; avio_skip(pb, size)) {
@@ -263,12 +263,10 @@ static int mmf_read_packet(AVFormatContext *s,
                            AVPacket *pkt)
 {
     MMFContext *mmf = s->priv_data;
-    AVStream *st;
     int ret, size;
 
     if (s->pb->eof_reached)
         return AVERROR(EIO);
-    st = s->streams[0];
 
     size = MAX_SIZE;
     if(size > mmf->data_size)
diff --git a/libavformat/mov.c b/libavformat/mov.c
index cede1f751a..8ec0d19ed2 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -464,21 +464,21 @@ static int mov_read_hdlr(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 int ff_mov_read_esds(AVFormatContext *fc, AVIOContext *pb, MOVAtom atom)
 {
     AVStream *st;
-    int tag, len;
+    int tag;
 
     if (fc->nb_streams < 1)
         return 0;
     st = fc->streams[fc->nb_streams-1];
 
     avio_rb32(pb); /* version + flags */
-    len = ff_mp4_read_descr(fc, pb, &tag);
+    ff_mp4_read_descr(fc, pb, &tag);
     if (tag == MP4ESDescrTag) {
         avio_rb16(pb); /* ID */
         avio_r8(pb); /* priority */
     } else
         avio_rb16(pb); /* ID */
 
-    len = ff_mp4_read_descr(fc, pb, &tag);
+    ff_mp4_read_descr(fc, pb, &tag);
     if (tag == MP4DecConfigDescrTag)
         ff_mp4_read_dec_config_descr(fc, st, pb);
     return 0;
diff --git a/libavformat/oggdec.c b/libavformat/oggdec.c
index 67678059a1..9562ea9ec0 100644
--- a/libavformat/oggdec.c
+++ b/libavformat/oggdec.c
@@ -196,8 +196,6 @@ static int ogg_read_page(AVFormatContext *s, int *str)
     int flags, nsegs;
     uint64_t gp;
     uint32_t serial;
-    uint32_t seq;
-    uint32_t crc;
     int size, idx;
     uint8_t sync[4];
     int sp = 0;
@@ -230,8 +228,7 @@ static int ogg_read_page(AVFormatContext *s, int *str)
     flags = avio_r8(bc);
     gp = avio_rl64 (bc);
     serial = avio_rl32 (bc);
-    seq = avio_rl32 (bc);
-    crc = avio_rl32 (bc);
+    avio_skip(bc, 8); /* seq, crc */
     nsegs = avio_r8(bc);
 
     idx = ogg_find_stream (ogg, serial);
diff --git a/libavformat/oggparseogm.c b/libavformat/oggparseogm.c
index dda5be601a..9526c3acc1 100644
--- a/libavformat/oggparseogm.c
+++ b/libavformat/oggparseogm.c
@@ -39,7 +39,6 @@ ogm_header(AVFormatContext *s, int idx)
     const uint8_t *p = os->buf + os->pstart;
     uint64_t time_unit;
     uint64_t spu;
-    uint32_t default_len;
 
     if(!(*p & 1))
         return 0;
@@ -74,8 +73,7 @@ ogm_header(AVFormatContext *s, int idx)
 
         time_unit   = bytestream_get_le64(&p);
         spu         = bytestream_get_le64(&p);
-        default_len = bytestream_get_le32(&p);
-
+        p += 4;                     /* default_len */
         p += 8;                     /* buffersize + bits_per_sample */
 
         if(st->codec->codec_type == AVMEDIA_TYPE_VIDEO){
diff --git a/libavformat/rl2.c b/libavformat/rl2.c
index f2d68384b8..b4172c284a 100644
--- a/libavformat/rl2.c
+++ b/libavformat/rl2.c
@@ -80,8 +80,6 @@ static av_cold int rl2_read_header(AVFormatContext *s,
     unsigned int audio_frame_counter = 0;
     unsigned int video_frame_counter = 0;
     unsigned int back_size;
-    int data_size;
-    unsigned short encoding_method;
     unsigned short sound_rate;
     unsigned short rate;
     unsigned short channels;
@@ -98,14 +96,14 @@ static av_cold int rl2_read_header(AVFormatContext *s,
     avio_skip(pb,4);          /* skip FORM tag */
     back_size = avio_rl32(pb); /**< get size of the background frame */
     signature = avio_rb32(pb);
-    data_size = avio_rb32(pb);
+    avio_skip(pb, 4);         /* data size */
     frame_count = avio_rl32(pb);
 
     /* disallow back_sizes and frame_counts that may lead to overflows later */
     if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))
         return AVERROR_INVALIDDATA;
 
-    encoding_method = avio_rl16(pb);
+    avio_skip(pb, 2);         /* encoding mentod */
     sound_rate = avio_rl16(pb);
     rate = avio_rl16(pb);
     channels = avio_rl16(pb);
diff --git a/libavformat/rmdec.c b/libavformat/rmdec.c
index 843706dec3..d6a5251c05 100644
--- a/libavformat/rmdec.c
+++ b/libavformat/rmdec.c
@@ -280,7 +280,7 @@ ff_rm_read_mdpr_codecdata (AVFormatContext *s, AVIOContext *pb,
         if (rm_read_audio_stream_info(s, pb, st, rst, 0))
             return -1;
     } else {
-        int fps, fps2;
+        int fps;
         if (avio_rl32(pb) != MKTAG('V', 'I', 'D', 'O')) {
         fail1:
             av_log(st->codec, AV_LOG_ERROR, "Unsupported video codec\n");
@@ -298,7 +298,7 @@ ff_rm_read_mdpr_codecdata (AVFormatContext *s, AVIOContext *pb,
         fps= avio_rb16(pb);
         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
         avio_rb32(pb);
-        fps2= avio_rb16(pb);
+        avio_skip(pb, 2);
         avio_rb16(pb);
 
         if ((ret = rm_read_extradata(pb, st->codec, codec_data_size - (avio_tell(pb) - codec_pos))) < 0)
diff --git a/libavformat/rpl.c b/libavformat/rpl.c
index 1ca4a86d1b..935b81d7d8 100644
--- a/libavformat/rpl.c
+++ b/libavformat/rpl.c
@@ -299,9 +299,9 @@ static int rpl_read_packet(AVFormatContext *s, AVPacket *pkt)
         stream->codec->codec_tag == 124) {
         // We have to split Escape 124 frames because there are
         // multiple frames per chunk in Escape 124 samples.
-        uint32_t frame_size, frame_flags;
+        uint32_t frame_size;
 
-        frame_flags = avio_rl32(pb);
+        avio_skip(pb, 4); /* flags */
         frame_size = avio_rl32(pb);
         if (avio_seek(pb, -8, SEEK_CUR) < 0)
             return AVERROR(EIO);
diff --git a/libavformat/rtpdec_latm.c b/libavformat/rtpdec_latm.c
index bde34b7ab9..42317a9529 100644
--- a/libavformat/rtpdec_latm.c
+++ b/libavformat/rtpdec_latm.c
@@ -108,8 +108,7 @@ static int parse_fmtp_config(AVStream *st, char *value)
     int len = ff_hex_to_data(NULL, value), i, ret = 0;
     GetBitContext gb;
     uint8_t *config;
-    int audio_mux_version, same_time_framing, num_sub_frames,
-        num_programs, num_layers;
+    int audio_mux_version, same_time_framing, num_programs, num_layers;
 
     /* Pad this buffer, too, to avoid out of bounds reads with get_bits below */
     config = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
@@ -119,7 +118,7 @@ static int parse_fmtp_config(AVStream *st, char *value)
     init_get_bits(&gb, config, len*8);
     audio_mux_version = get_bits(&gb, 1);
     same_time_framing = get_bits(&gb, 1);
-    num_sub_frames    = get_bits(&gb, 6);
+    skip_bits(&gb, 6); /* num_sub_frames */
     num_programs      = get_bits(&gb, 4);
     num_layers        = get_bits(&gb, 3);
     if (audio_mux_version != 0 || same_time_framing != 1 || num_programs != 0 ||
diff --git a/libavformat/sauce.c b/libavformat/sauce.c
index cf33ab7be7..f9ca17ac30 100644
--- a/libavformat/sauce.c
+++ b/libavformat/sauce.c
@@ -32,7 +32,7 @@ int ff_sauce_read(AVFormatContext *avctx, uint64_t *fsize, int *got_width, int g
 {
     AVIOContext *pb = avctx->pb;
     char buf[36];
-    int datatype, filetype, t1, t2, nb_comments, flags;
+    int datatype, filetype, t1, t2, nb_comments;
     uint64_t start_pos = avio_size(pb) - 128;
 
     avio_seek(pb, start_pos, SEEK_SET);
@@ -57,7 +57,7 @@ int ff_sauce_read(AVFormatContext *avctx, uint64_t *fsize, int *got_width, int g
     t1          = avio_rl16(pb);
     t2          = avio_rl16(pb);
     nb_comments = avio_r8(pb);
-    flags       = avio_r8(pb);
+    avio_skip(pb, 1); /* flags */
     avio_skip(pb, 4);
     GET_SAUCE_META("encoder",   22);
 
diff --git a/libavformat/smacker.c b/libavformat/smacker.c
index 01d1303ae3..db9a02bb6c 100644
--- a/libavformat/smacker.c
+++ b/libavformat/smacker.c
@@ -233,7 +233,6 @@ static int smacker_read_packet(AVFormatContext *s, AVPacket *pkt)
     int i;
     int frame_size = 0;
     int palchange = 0;
-    int pos;
 
     if (s->pb->eof_reached || smk->cur_frame >= smk->frames)
         return AVERROR_EOF;
@@ -244,7 +243,6 @@ static int smacker_read_packet(AVFormatContext *s, AVPacket *pkt)
         frame_size = smk->frm_size[smk->cur_frame] & (~3);
         flags = smk->frm_flags[smk->cur_frame];
         /* handle palette change event */
-        pos = avio_tell(s->pb);
         if(flags & SMACKER_PAL){
             int size, sz, t, off, j, pos;
             uint8_t *pal = smk->pal;
diff --git a/libavformat/sol.c b/libavformat/sol.c
index 1c9ce69538..1ebb4d2e30 100644
--- a/libavformat/sol.c
+++ b/libavformat/sol.c
@@ -85,7 +85,6 @@ static int sol_channels(int magic, int type)
 static int sol_read_header(AVFormatContext *s,
                           AVFormatParameters *ap)
 {
-    int size;
     unsigned int magic,tag;
     AVIOContext *pb = s->pb;
     unsigned int id, channels, rate, type;
@@ -99,7 +98,7 @@ static int sol_read_header(AVFormatContext *s,
         return -1;
     rate = avio_rl16(pb);
     type = avio_r8(pb);
-    size = avio_rl32(pb);
+    avio_skip(pb, 4); /* size */
     if (magic != 0x0B8D)
         avio_r8(pb); /* newer SOLs contain padding byte */
 
diff --git a/libavformat/yuv4mpeg.c b/libavformat/yuv4mpeg.c
index d712321162..9a6a0c8315 100644
--- a/libavformat/yuv4mpeg.c
+++ b/libavformat/yuv4mpeg.c
@@ -94,7 +94,7 @@ static int yuv4_write_packet(AVFormatContext *s, AVPacket *pkt)
     AVPicture *picture;
     int* first_pkt = s->priv_data;
     int width, height, h_chroma_shift, v_chroma_shift;
-    int i, m;
+    int i;
     char buf2[Y4M_LINE_MAX+1];
     char buf1[20];
     uint8_t *ptr, *ptr1, *ptr2;
@@ -114,7 +114,7 @@ static int yuv4_write_packet(AVFormatContext *s, AVPacket *pkt)
 
     /* construct frame header */
 
-    m = snprintf(buf1, sizeof(buf1), "%s\n", Y4M_FRAME_MAGIC);
+    snprintf(buf1, sizeof(buf1), "%s\n", Y4M_FRAME_MAGIC);
     avio_write(pb, buf1, strlen(buf1));
 
     width = st->codec->width;