lavf: replace AVStream.codec with AVStream.codecpar

Currently, AVStream contains an embedded AVCodecContext instance, which
is used by demuxers to export stream parameters to the caller and by
muxers to receive stream parameters from the caller. It is also used
internally as the codec context that is passed to parsers.

In addition, it is also widely used by the callers as the decoding (when
demuxer) or encoding (when muxing) context, though this has been
officially discouraged since Libav 11.

There are multiple important problems with this approach:
    - the fields in AVCodecContext are in general one of
        * stream parameters
        * codec options
        * codec state
      However, it's not clear which ones are which. It is consequently
      unclear which fields are a demuxer allowed to set or a muxer allowed to
      read. This leads to erratic behaviour depending on whether decoding or
      encoding is being performed or not (and whether it uses the AVStream
      embedded codec context).
    - various synchronization issues arising from the fact that the same
      context is used by several different APIs (muxers/demuxers,
      parsers, bitstream filters and encoders/decoders) simultaneously, with
      there being no clear rules for who can modify what and the different
      processes being typically delayed with respect to each other.
    - avformat_find_stream_info() making it necessary to support opening
      and closing a single codec context multiple times, thus
      complicating the semantics of freeing various allocated objects in the
      codec context.

Those problems are resolved by replacing the AVStream embedded codec
context with a newly added AVCodecParameters instance, which stores only
the stream parameters exported by the demuxers or read by the muxers.

1 files changed, 51 insertions, 51 deletions

diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index 01af597894..63e333b505 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -639,8 +639,8 @@ static void mpegts_find_stream_type(AVStream *st,
 {
     for (; types->stream_type; types++)
         if (stream_type == types->stream_type) {
-            st->codec->codec_type = types->codec_type;
-            st->codec->codec_id   = types->codec_id;
+            st->codecpar->codec_type = types->codec_type;
+            st->codecpar->codec_id   = types->codec_id;
             return;
         }
 }
@@ -650,8 +650,8 @@ static int mpegts_set_stream_info(AVStream *st, PESContext *pes,
 {
     avpriv_set_pts_info(st, 33, 1, 90000);
     st->priv_data         = pes;
-    st->codec->codec_type = AVMEDIA_TYPE_DATA;
-    st->codec->codec_id   = AV_CODEC_ID_NONE;
+    st->codecpar->codec_type = AVMEDIA_TYPE_DATA;
+    st->codecpar->codec_id   = AV_CODEC_ID_NONE;
     st->need_parsing      = AVSTREAM_PARSE_FULL;
     pes->st          = st;
     pes->stream_type = stream_type;
@@ -660,11 +660,11 @@ static int mpegts_set_stream_info(AVStream *st, PESContext *pes,
            "stream=%d stream_type=%x pid=%x prog_reg_desc=%.4s\n",
            st->index, pes->stream_type, pes->pid, (char *)&prog_reg_desc);
 
-    st->codec->codec_tag = pes->stream_type;
+    st->codecpar->codec_tag = pes->stream_type;
 
     mpegts_find_stream_type(st, pes->stream_type, ISO_types);
     if (prog_reg_desc == AV_RL32("HDMV") &&
-        st->codec->codec_id == AV_CODEC_ID_NONE) {
+        st->codecpar->codec_id == AV_CODEC_ID_NONE) {
         mpegts_find_stream_type(st, pes->stream_type, HDMV_types);
         if (pes->stream_type == 0x83) {
             // HDMV TrueHD streams also contain an AC3 coded version of the
@@ -685,13 +685,13 @@ static int mpegts_set_stream_info(AVStream *st, PESContext *pes,
             sub_st->id = pes->pid;
             avpriv_set_pts_info(sub_st, 33, 1, 90000);
             sub_st->priv_data         = sub_pes;
-            sub_st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
-            sub_st->codec->codec_id   = AV_CODEC_ID_AC3;
+            sub_st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
+            sub_st->codecpar->codec_id   = AV_CODEC_ID_AC3;
             sub_st->need_parsing      = AVSTREAM_PARSE_FULL;
             sub_pes->sub_st           = pes->sub_st = sub_st;
         }
     }
-    if (st->codec->codec_id == AV_CODEC_ID_NONE)
+    if (st->codecpar->codec_id == AV_CODEC_ID_NONE)
         mpegts_find_stream_type(st, pes->stream_type, MISC_types);
 
     return 0;
@@ -873,12 +873,12 @@ static int mpegts_push_data(MpegTSFilter *filter,
                         code != 0x1ff && code != 0x1f2 && /* program_stream_directory, DSMCC_stream */
                         code != 0x1f8) {                  /* ITU-T Rec. H.222.1 type E stream */
                         pes->state = MPEGTS_PESHEADER;
-                        if (pes->st->codec->codec_id == AV_CODEC_ID_NONE) {
+                        if (pes->st->codecpar->codec_id == AV_CODEC_ID_NONE) {
                             av_log(pes->stream, AV_LOG_TRACE,
                                     "pid=%x stream_type=%x probing\n",
                                     pes->pid,
                                     pes->stream_type);
-                            pes->st->codec->codec_id = AV_CODEC_ID_PROBE;
+                            pes->st->codecpar->codec_id = AV_CODEC_ID_PROBE;
                         }
                     } else {
                         pes->state      = MPEGTS_PAYLOAD;
@@ -1304,14 +1304,14 @@ static void m4sl_cb(MpegTSFilter *filter, const uint8_t *section,
                               mp4_descr[i].dec_config_descr_len, 0,
                               NULL, NULL, NULL, NULL);
             ff_mp4_read_dec_config_descr(s, st, &pb);
-            if (st->codec->codec_id == AV_CODEC_ID_AAC &&
-                st->codec->extradata_size > 0)
+            if (st->codecpar->codec_id == AV_CODEC_ID_AAC &&
+                st->codecpar->extradata_size > 0)
                 st->need_parsing = 0;
-            if (st->codec->codec_id == AV_CODEC_ID_H264 &&
-                st->codec->extradata_size > 0)
+            if (st->codecpar->codec_id == AV_CODEC_ID_H264 &&
+                st->codecpar->extradata_size > 0)
                 st->need_parsing = 0;
 
-            st->codec->codec_type = avcodec_get_type(st->codec->codec_id);
+            st->codecpar->codec_type = avcodec_get_type(st->codecpar->codec_id);
         }
     }
     for (i = 0; i < mp4_descr_count; i++)
@@ -1359,7 +1359,7 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type
 
     av_log(fc, AV_LOG_TRACE, "tag: 0x%02x len=%d\n", desc_tag, desc_len);
 
-    if (st->codec->codec_id == AV_CODEC_ID_NONE &&
+    if (st->codecpar->codec_id == AV_CODEC_ID_NONE &&
         stream_type == STREAM_TYPE_PRIVATE_DATA)
         mpegts_find_stream_type(st, desc_tag, DESC_types);
 
@@ -1378,10 +1378,10 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type
                                   mp4_descr[i].dec_config_descr_len, 0,
                                   NULL, NULL, NULL, NULL);
                 ff_mp4_read_dec_config_descr(fc, st, &pb);
-                if (st->codec->codec_id == AV_CODEC_ID_AAC &&
-                    st->codec->extradata_size > 0)
+                if (st->codecpar->codec_id == AV_CODEC_ID_AAC &&
+                    st->codecpar->extradata_size > 0)
                     st->need_parsing = 0;
-                if (st->codec->codec_id == AV_CODEC_ID_MPEG4SYSTEMS)
+                if (st->codecpar->codec_id == AV_CODEC_ID_MPEG4SYSTEMS)
                     mpegts_open_section_filter(ts, pid, m4sl_cb, ts, 1);
             }
         break;
@@ -1389,15 +1389,15 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type
         if (get16(pp, desc_end) < 0)
             break;
         if (mp4_descr_count > 0 &&
-            st->codec->codec_id == AV_CODEC_ID_AAC_LATM &&
+            st->codecpar->codec_id == AV_CODEC_ID_AAC_LATM &&
             mp4_descr->dec_config_descr_len && mp4_descr->es_id == pid) {
             AVIOContext pb;
             ffio_init_context(&pb, mp4_descr->dec_config_descr,
                               mp4_descr->dec_config_descr_len, 0,
                               NULL, NULL, NULL, NULL);
             ff_mp4_read_dec_config_descr(fc, st, &pb);
-            if (st->codec->codec_id == AV_CODEC_ID_AAC &&
-                st->codec->extradata_size > 0)
+            if (st->codecpar->codec_id == AV_CODEC_ID_AAC &&
+                st->codecpar->extradata_size > 0)
                 st->need_parsing = 0;
         }
         break;
@@ -1424,15 +1424,15 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type
             st->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
             break;
         }
-        if (st->codec->extradata) {
-            if (st->codec->extradata_size == 4 &&
-                memcmp(st->codec->extradata, *pp, 4))
+        if (st->codecpar->extradata) {
+            if (st->codecpar->extradata_size == 4 &&
+                memcmp(st->codecpar->extradata, *pp, 4))
                 avpriv_request_sample(fc, "DVB sub with multiple IDs");
         } else {
-            st->codec->extradata = av_malloc(4 + AV_INPUT_BUFFER_PADDING_SIZE);
-            if (st->codec->extradata) {
-                st->codec->extradata_size = 4;
-                memcpy(st->codec->extradata, *pp, 4);
+            st->codecpar->extradata = av_malloc(4 + AV_INPUT_BUFFER_PADDING_SIZE);
+            if (st->codecpar->extradata) {
+                st->codecpar->extradata_size = 4;
+                memcpy(st->codecpar->extradata, *pp, 4);
             }
         }
         *pp += 4;
@@ -1462,35 +1462,35 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type
         }
         break;
     case 0x05: /* registration descriptor */
-        st->codec->codec_tag = bytestream_get_le32(pp);
-        av_log(fc, AV_LOG_TRACE, "reg_desc=%.4s\n", (char *)&st->codec->codec_tag);
-        if (st->codec->codec_id == AV_CODEC_ID_NONE)
-            mpegts_find_stream_type(st, st->codec->codec_tag, REGD_types);
+        st->codecpar->codec_tag = bytestream_get_le32(pp);
+        av_log(fc, AV_LOG_TRACE, "reg_desc=%.4s\n", (char *)&st->codecpar->codec_tag);
+        if (st->codecpar->codec_id == AV_CODEC_ID_NONE)
+            mpegts_find_stream_type(st, st->codecpar->codec_tag, REGD_types);
         break;
     case 0x7f: /* DVB extension descriptor */
         ext_desc_tag = get8(pp, desc_end);
         if (ext_desc_tag < 0)
             return AVERROR_INVALIDDATA;
-        if (st->codec->codec_id == AV_CODEC_ID_OPUS &&
+        if (st->codecpar->codec_id == AV_CODEC_ID_OPUS &&
             ext_desc_tag == 0x80) { /* User defined (provisional Opus) */
-            if (!st->codec->extradata) {
-                st->codec->extradata = av_mallocz(sizeof(opus_default_extradata) +
-                                                  AV_INPUT_BUFFER_PADDING_SIZE);
-                if (!st->codec->extradata)
+            if (!st->codecpar->extradata) {
+                st->codecpar->extradata = av_mallocz(sizeof(opus_default_extradata) +
+                                                     AV_INPUT_BUFFER_PADDING_SIZE);
+                if (!st->codecpar->extradata)
                     return AVERROR(ENOMEM);
 
-                st->codec->extradata_size = sizeof(opus_default_extradata);
-                memcpy(st->codec->extradata, opus_default_extradata, sizeof(opus_default_extradata));
+                st->codecpar->extradata_size = sizeof(opus_default_extradata);
+                memcpy(st->codecpar->extradata, opus_default_extradata, sizeof(opus_default_extradata));
 
                 channel_config_code = get8(pp, desc_end);
                 if (channel_config_code < 0)
                     return AVERROR_INVALIDDATA;
                 if (channel_config_code <= 0x8) {
-                    st->codec->extradata[9]  = channels = channel_config_code ? channel_config_code : 2;
-                    st->codec->extradata[18] = channel_config_code ? (channels > 2) : 255;
-                    st->codec->extradata[19] = opus_stream_cnt[channel_config_code];
-                    st->codec->extradata[20] = opus_coupled_stream_cnt[channel_config_code];
-                    memcpy(&st->codec->extradata[21], opus_channel_map[channels - 1], channels);
+                    st->codecpar->extradata[9]  = channels = channel_config_code ? channel_config_code : 2;
+                    st->codecpar->extradata[18] = channel_config_code ? (channels > 2) : 255;
+                    st->codecpar->extradata[19] = opus_stream_cnt[channel_config_code];
+                    st->codecpar->extradata[20] = opus_coupled_stream_cnt[channel_config_code];
+                    memcpy(&st->codecpar->extradata[21], opus_channel_map[channels - 1], channels);
                 } else {
                     avpriv_request_sample(fc, "Opus in MPEG-TS - channel_config_code > 0x8");
                 }
@@ -1617,7 +1617,7 @@ static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len
             } else {
                 st = avformat_new_stream(ts->stream, NULL);
                 st->id = pid;
-                st->codec->codec_type = AVMEDIA_TYPE_DATA;
+                st->codecpar->codec_type = AVMEDIA_TYPE_DATA;
             }
         }
 
@@ -1648,7 +1648,7 @@ static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len
                 stream_type == 0x83 && pes->sub_st) {
                 ff_program_add_stream_index(ts->stream, h->id,
                                             pes->sub_st->index);
-                pes->sub_st->codec->codec_tag = st->codec->codec_tag;
+                pes->sub_st->codecpar->codec_tag = st->codecpar->codec_tag;
             }
         }
         p = desc_list_end;
@@ -2104,8 +2104,8 @@ static int mpegts_read_header(AVFormatContext *s)
         if (!st)
             return AVERROR(ENOMEM);
         avpriv_set_pts_info(st, 60, 1, 27000000);
-        st->codec->codec_type = AVMEDIA_TYPE_DATA;
-        st->codec->codec_id   = AV_CODEC_ID_MPEG2TS;
+        st->codecpar->codec_type = AVMEDIA_TYPE_DATA;
+        st->codecpar->codec_id   = AV_CODEC_ID_MPEG2TS;
 
         /* we iterate until we find two PCRs to estimate the bitrate */
         pcr_pid    = -1;
@@ -2136,7 +2136,7 @@ static int mpegts_read_header(AVFormatContext *s)
         ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]);
         ts->cur_pcr  = pcrs[0] - ts->pcr_incr * packet_count[0];
         s->bit_rate  = TS_PACKET_SIZE * 8 * 27e6 / ts->pcr_incr;
-        st->codec->bit_rate = s->bit_rate;
+        st->codecpar->bit_rate = s->bit_rate;
         st->start_time      = ts->cur_pcr;
         av_log(ts->stream, AV_LOG_TRACE, "start=%0.3f pcr=%0.3f incr=%d\n",
                 st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr);