adds descriptions to the libavcodec AVOptions array, taken from the

OptionDef options[] array.
Patch by Takis,
Original thread:
Date: Sep 11, 2006 3:39 PM
Subject: [Ffmpeg-devel] [PATCH] AVOptions description sync

Originally committed as revision 6243 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 39 insertions, 39 deletions

diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 79ad8fa181..7e1f9de65c 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -450,8 +450,8 @@ static const char* context_to_name(void* ptr) {
 #define AV_CODEC_DEFAULT_BITRATE 800*1000
 
 static const AVOption options[]={
-{"bit_rate", NULL, OFFSET(bit_rate), FF_OPT_TYPE_INT, AV_CODEC_DEFAULT_BITRATE, INT_MIN, INT_MAX, V|A|E},
-{"bit_rate_tolerance", NULL, OFFSET(bit_rate_tolerance), FF_OPT_TYPE_INT, AV_CODEC_DEFAULT_BITRATE*10, INT_MIN, INT_MAX, V|E},
+{"bit_rate", "set video bitrate (in bits/s)", OFFSET(bit_rate), FF_OPT_TYPE_INT, AV_CODEC_DEFAULT_BITRATE, INT_MIN, INT_MAX, V|A|E},
+{"bit_rate_tolerance", "set video bitrate tolerance (in bits/s)", OFFSET(bit_rate_tolerance), FF_OPT_TYPE_INT, AV_CODEC_DEFAULT_BITRATE*10, INT_MIN, INT_MAX, V|E},
 {"flags", NULL, OFFSET(flags), FF_OPT_TYPE_FLAGS, DEFAULT, INT_MIN, INT_MAX, V|A|E|D, "flags"},
 {"mv4", "use four motion vector by macroblock (mpeg4)", 0, FF_OPT_TYPE_CONST, CODEC_FLAG_4MV, INT_MIN, INT_MAX, V|E, "flags"},
 {"obmc", "use overlapped block motion compensation (h263+)", 0, FF_OPT_TYPE_CONST, CODEC_FLAG_OBMC, INT_MIN, INT_MAX, V|E, "flags"},
@@ -490,25 +490,25 @@ static const AVOption options[]={
 {"noout", "skip bitstream encoding", 0, FF_OPT_TYPE_CONST, CODEC_FLAG2_NO_OUTPUT, INT_MIN, INT_MAX, V|E, "flags2"},
 {"local_header", "place global headers at every keyframe instead of in extradata", 0, FF_OPT_TYPE_CONST, CODEC_FLAG2_LOCAL_HEADER, INT_MIN, INT_MAX, V|E, "flags2"},
 {"sub_id", NULL, OFFSET(sub_id), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
-{"me_method", NULL, OFFSET(me_method), FF_OPT_TYPE_INT, ME_EPZS, INT_MIN, INT_MAX, V|E, "me_method"},
+{"me_method", "set motion estimation method", OFFSET(me_method), FF_OPT_TYPE_INT, ME_EPZS, INT_MIN, INT_MAX, V|E, "me_method"},
 {"extradata_size", NULL, OFFSET(extradata_size), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
 {"time_base", NULL, OFFSET(time_base), FF_OPT_TYPE_RATIONAL, DEFAULT, INT_MIN, INT_MAX},
-{"gop_size", NULL, OFFSET(gop_size), FF_OPT_TYPE_INT, 50, INT_MIN, INT_MAX, V|E},
+{"gop_size", "set the group of picture size", OFFSET(gop_size), FF_OPT_TYPE_INT, 50, INT_MIN, INT_MAX, V|E},
 {"rate_emu", NULL, OFFSET(rate_emu), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
-{"sample_rate", NULL, OFFSET(sample_rate), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
-{"channels", NULL, OFFSET(channels), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
+{"sample_rate", "set audio sampling rate (in Hz)", OFFSET(sample_rate), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
+{"channels", "set number of audio channels", OFFSET(channels), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
 {"cutoff", "set cutoff bandwidth", OFFSET(cutoff), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, A|E},
 {"frame_size", NULL, OFFSET(frame_size), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, A|E},
 {"frame_number", NULL, OFFSET(frame_number), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
 {"real_pict_num", NULL, OFFSET(real_pict_num), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
 {"delay", NULL, OFFSET(delay), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
-{"qcompress", NULL, OFFSET(qcompress), FF_OPT_TYPE_FLOAT, 0.5, FLT_MIN, FLT_MAX, V|E},
-{"qblur", NULL, OFFSET(qblur), FF_OPT_TYPE_FLOAT, DEFAULT, FLT_MIN, FLT_MAX, V|E},
-{"qmin", NULL, OFFSET(qmin), FF_OPT_TYPE_INT, 2, 0, INT_MAX, V|E},
-{"qmax", NULL, OFFSET(qmax), FF_OPT_TYPE_INT, 31, 0, INT_MAX, V|E},
-{"max_qdiff", NULL, OFFSET(max_qdiff), FF_OPT_TYPE_INT, 3, INT_MIN, INT_MAX, V|E},
-{"max_b_frames", NULL, OFFSET(max_b_frames), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
-{"b_quant_factor", NULL, OFFSET(b_quant_factor), FF_OPT_TYPE_FLOAT, 1.25, FLT_MIN, FLT_MAX, V|E},
+{"qcompress", "video quantiser scale compression (VBR)", OFFSET(qcompress), FF_OPT_TYPE_FLOAT, 0.5, FLT_MIN, FLT_MAX, V|E},
+{"qblur", "video quantiser scale blur (VBR)", OFFSET(qblur), FF_OPT_TYPE_FLOAT, DEFAULT, FLT_MIN, FLT_MAX, V|E},
+{"qmin", "min video quantiser scale (VBR)", OFFSET(qmin), FF_OPT_TYPE_INT, 2, 0, INT_MAX, V|E},
+{"qmax", "max video quantiser scale (VBR)", OFFSET(qmax), FF_OPT_TYPE_INT, 31, 0, INT_MAX, V|E},
+{"max_qdiff", "max difference between the quantiser scale (VBR)", OFFSET(max_qdiff), FF_OPT_TYPE_INT, 3, INT_MIN, INT_MAX, V|E},
+{"max_b_frames", "use 'frames' B frames", OFFSET(max_b_frames), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
+{"b_quant_factor", "qp factor between p and b frames", OFFSET(b_quant_factor), FF_OPT_TYPE_FLOAT, 1.25, FLT_MIN, FLT_MAX, V|E},
 {"rc_strategy", NULL, OFFSET(rc_strategy), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"b_strategy", NULL, OFFSET(b_frame_strategy), FF_OPT_TYPE_INT, 0, INT_MIN, INT_MAX, V|E},
 {"hurry_up", NULL, OFFSET(hurry_up), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|D},
@@ -524,7 +524,7 @@ static const AVOption options[]={
 {"misc_bits", NULL, OFFSET(misc_bits), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
 {"frame_bits", NULL, OFFSET(frame_bits), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
 {"codec_tag", NULL, OFFSET(codec_tag), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
-{"bugs", NULL, OFFSET(workaround_bugs), FF_OPT_TYPE_INT, FF_BUG_AUTODETECT, INT_MIN, INT_MAX, V|D, "bug"},
+{"bugs", "workaround not auto detected encoder bugs", OFFSET(workaround_bugs), FF_OPT_TYPE_INT, FF_BUG_AUTODETECT, INT_MIN, INT_MAX, V|D, "bug"},
 {"autodetect", NULL, 0, FF_OPT_TYPE_CONST, FF_BUG_AUTODETECT, INT_MIN, INT_MAX, V|D, "bug"},
 {"old_msmpeg4", NULL, 0, FF_OPT_TYPE_CONST, FF_BUG_OLD_MSMPEG4, INT_MIN, INT_MAX, V|D, "bug"},
 {"xvid_ilace", NULL, 0, FF_OPT_TYPE_CONST, FF_BUG_XVID_ILACE, INT_MIN, INT_MAX, V|D, "bug"},
@@ -542,13 +542,13 @@ static const AVOption options[]={
 {"ms", NULL, 0, FF_OPT_TYPE_CONST, FF_BUG_MS, INT_MIN, INT_MAX, V|D, "bug"},
 {"lelim", "single coefficient elimination threshold for luminance (negative values also consider dc coefficient)", OFFSET(luma_elim_threshold), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"celim", "single coefficient elimination threshold for chrominance (negative values also consider dc coefficient)", OFFSET(chroma_elim_threshold), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
-{"strict", NULL, OFFSET(strict_std_compliance), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E, "strict"},
+{"strict", "how strictly to follow the standards", OFFSET(strict_std_compliance), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E, "strict"},
 {"very", NULL, 0, FF_OPT_TYPE_CONST, FF_COMPLIANCE_VERY_STRICT, INT_MIN, INT_MAX, V|E, "strict"},
 {"strict", NULL, 0, FF_OPT_TYPE_CONST, FF_COMPLIANCE_STRICT, INT_MIN, INT_MAX, V|E, "strict"},
 {"normal", NULL, 0, FF_OPT_TYPE_CONST, FF_COMPLIANCE_NORMAL, INT_MIN, INT_MAX, V|E, "strict"},
 {"inofficial", NULL, 0, FF_OPT_TYPE_CONST, FF_COMPLIANCE_INOFFICIAL, INT_MIN, INT_MAX, V|E, "strict"},
 {"experimental", NULL, 0, FF_OPT_TYPE_CONST, FF_COMPLIANCE_EXPERIMENTAL, INT_MIN, INT_MAX, V|E, "strict"},
-{"b_quant_offset", NULL, OFFSET(b_quant_offset), FF_OPT_TYPE_FLOAT, 1.25, FLT_MIN, FLT_MAX, V|E},
+{"b_quant_offset", "qp offset between p and b frames", OFFSET(b_quant_offset), FF_OPT_TYPE_FLOAT, 1.25, FLT_MIN, FLT_MAX, V|E},
 {"er", NULL, OFFSET(error_resilience), FF_OPT_TYPE_INT, FF_ER_CAREFUL, INT_MIN, INT_MAX, V|D, "er"},
 {"careful", NULL, 0, FF_OPT_TYPE_CONST, FF_ER_CAREFUL, INT_MIN, INT_MAX, V|D, "er"},
 {"compliant", NULL, 0, FF_OPT_TYPE_CONST, FF_ER_COMPLIANT, INT_MIN, INT_MAX, V|D, "er"},
@@ -560,18 +560,18 @@ static const AVOption options[]={
 {"mpeg_quant", NULL, OFFSET(mpeg_quant), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"stats_out", NULL, OFFSET(stats_out), FF_OPT_TYPE_STRING, DEFAULT, CHAR_MIN, CHAR_MAX},
 {"stats_in", NULL, OFFSET(stats_in), FF_OPT_TYPE_STRING, DEFAULT, CHAR_MIN, CHAR_MAX},
-{"rc_qsquish", NULL, OFFSET(rc_qsquish), FF_OPT_TYPE_FLOAT, DEFAULT, FLT_MIN, FLT_MAX, V|E},
+{"rc_qsquish", "how to keep quantiser between qmin and qmax (0 = clip, 1 = use differentiable function)", OFFSET(rc_qsquish), FF_OPT_TYPE_FLOAT, DEFAULT, FLT_MIN, FLT_MAX, V|E},
 {"rc_qmod_amp", NULL, OFFSET(rc_qmod_amp), FF_OPT_TYPE_FLOAT, DEFAULT, FLT_MIN, FLT_MAX, V|E},
 {"rc_qmod_freq", NULL, OFFSET(rc_qmod_freq), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"rc_override_count", NULL, OFFSET(rc_override_count), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
-{"rc_eq", NULL, OFFSET(rc_eq), FF_OPT_TYPE_STRING, DEFAULT, CHAR_MIN, CHAR_MAX, V|E},
-{"rc_max_rate", NULL, OFFSET(rc_max_rate), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
-{"rc_min_rate", NULL, OFFSET(rc_min_rate), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
-{"rc_buffer_size", NULL, OFFSET(rc_buffer_size), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
+{"rc_eq", "set rate control equation", OFFSET(rc_eq), FF_OPT_TYPE_STRING, DEFAULT, CHAR_MIN, CHAR_MAX, V|E},
+{"rc_max_rate", "set max video bitrate tolerance (in bits/s)", OFFSET(rc_max_rate), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
+{"rc_min_rate", "set min video bitrate tolerance (in bits/s)", OFFSET(rc_min_rate), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
+{"rc_buffer_size", "set ratecontrol buffer size (in bits)", OFFSET(rc_buffer_size), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"rc_buf_aggressivity", NULL, OFFSET(rc_buffer_aggressivity), FF_OPT_TYPE_FLOAT, DEFAULT, FLT_MIN, FLT_MAX, V|E},
-{"i_quant_factor", NULL, OFFSET(i_quant_factor), FF_OPT_TYPE_FLOAT, -0.8, FLT_MIN, FLT_MAX, V|E},
-{"i_quant_offset", NULL, OFFSET(i_quant_offset), FF_OPT_TYPE_FLOAT, 0.0, FLT_MIN, FLT_MAX, V|E},
-{"rc_initial_cplx", NULL, OFFSET(rc_initial_cplx), FF_OPT_TYPE_FLOAT, DEFAULT, FLT_MIN, FLT_MAX, V|E},
+{"i_quant_factor", "qp factor between p and i frames", OFFSET(i_quant_factor), FF_OPT_TYPE_FLOAT, -0.8, FLT_MIN, FLT_MAX, V|E},
+{"i_quant_offset", "qp offset between p and i frames", OFFSET(i_quant_offset), FF_OPT_TYPE_FLOAT, 0.0, FLT_MIN, FLT_MAX, V|E},
+{"rc_initial_cplx", "initial complexity for 1-pass encoding", OFFSET(rc_initial_cplx), FF_OPT_TYPE_FLOAT, DEFAULT, FLT_MIN, FLT_MAX, V|E},
 {"dct", NULL, OFFSET(dct_algo), FF_OPT_TYPE_INT, DEFAULT, 0, INT_MAX, V|E, "dct"},
 {"auto", NULL, 0, FF_OPT_TYPE_CONST, FF_DCT_AUTO, INT_MIN, INT_MAX, V|E, "dct"},
 {"fastint", NULL, 0, FF_OPT_TYPE_CONST, FF_DCT_FASTINT, INT_MIN, INT_MAX, V|E, "dct"},
@@ -640,7 +640,7 @@ static const AVOption options[]={
 {"ildctcmp", "interlaced dct compare function", OFFSET(ildct_cmp), FF_OPT_TYPE_INT, FF_CMP_VSAD, INT_MIN, INT_MAX, V|E, "cmp_func"},
 {"dia_size", NULL, OFFSET(dia_size), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"last_pred", NULL, OFFSET(last_predictor_count), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
-{"preme", NULL, OFFSET(pre_me), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
+{"preme", "pre motion estimation", OFFSET(pre_me), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"precmp", "pre motion estimation compare function", OFFSET(me_pre_cmp), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E, "cmp_func"},
 {"sad", NULL, 0, FF_OPT_TYPE_CONST, FF_CMP_SAD, INT_MIN, INT_MAX, V|E, "cmp_func"},
 {"sse", NULL, 0, FF_OPT_TYPE_CONST, FF_CMP_SSE, INT_MIN, INT_MAX, V|E, "cmp_func"},
@@ -662,9 +662,9 @@ static const AVOption options[]={
 {"pre_dia_size", NULL, OFFSET(pre_dia_size), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"subq", "sub pel motion estimation quality", OFFSET(me_subpel_quality), FF_OPT_TYPE_INT, 8, INT_MIN, INT_MAX, V|E},
 {"dtg_active_format", NULL, OFFSET(dtg_active_format), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
-{"me_range", NULL, OFFSET(me_range), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
-{"ibias", NULL, OFFSET(intra_quant_bias), FF_OPT_TYPE_INT, FF_DEFAULT_QUANT_BIAS, INT_MIN, INT_MAX, V|E},
-{"pbias", NULL, OFFSET(inter_quant_bias), FF_OPT_TYPE_INT, FF_DEFAULT_QUANT_BIAS, INT_MIN, INT_MAX, V|E},
+{"me_range", "limit motion vectors range (1023 for DivX player)", OFFSET(me_range), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
+{"ibias", "intra quant bias", OFFSET(intra_quant_bias), FF_OPT_TYPE_INT, FF_DEFAULT_QUANT_BIAS, INT_MIN, INT_MAX, V|E},
+{"pbias", "inter quant bias", OFFSET(inter_quant_bias), FF_OPT_TYPE_INT, FF_DEFAULT_QUANT_BIAS, INT_MIN, INT_MAX, V|E},
 {"color_table_id", NULL, OFFSET(color_table_id), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
 {"internal_buffer_count", NULL, OFFSET(internal_buffer_count), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
 {"global_quality", NULL, OFFSET(global_quality), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
@@ -679,9 +679,9 @@ static const AVOption options[]={
 {"bits", NULL, 0, FF_OPT_TYPE_CONST, FF_MB_DECISION_BITS, INT_MIN, INT_MAX, V|E, "mbd"},
 {"rd", NULL, 0, FF_OPT_TYPE_CONST, FF_MB_DECISION_RD, INT_MIN, INT_MAX, V|E, "mbd"},
 {"stream_codec_tag", NULL, OFFSET(stream_codec_tag), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
-{"sc_threshold", NULL, OFFSET(scenechange_threshold), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
-{"lmin", "min lagrange factor", OFFSET(lmin), FF_OPT_TYPE_INT,  2*FF_QP2LAMBDA, 0, INT_MAX, V|E},
-{"lmax", "max lagrange factor", OFFSET(lmax), FF_OPT_TYPE_INT, 31*FF_QP2LAMBDA, 0, INT_MAX, V|E},
+{"sc_threshold", "scene change threshold", OFFSET(scenechange_threshold), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
+{"lmin", "min lagrange factor (VBR)", OFFSET(lmin), FF_OPT_TYPE_INT,  2*FF_QP2LAMBDA, 0, INT_MAX, V|E},
+{"lmax", "max lagrange factor (VBR)", OFFSET(lmax), FF_OPT_TYPE_INT, 31*FF_QP2LAMBDA, 0, INT_MAX, V|E},
 {"nr", "noise reduction", OFFSET(noise_reduction), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"rc_init_occupancy", NULL, OFFSET(rc_initial_buffer_occupancy), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"inter_threshold", NULL, OFFSET(inter_threshold), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
@@ -695,8 +695,8 @@ static const AVOption options[]={
 {"qns", "quantizer noise shaping", OFFSET(quantizer_noise_shaping), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"thread_count", NULL, OFFSET(thread_count), FF_OPT_TYPE_INT, 1, INT_MIN, INT_MAX, V|E|D},
 {"me_threshold", "motion estimaton threshold", OFFSET(me_threshold), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
-{"mb_threshold", NULL, OFFSET(mb_threshold), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
-{"dc", NULL, OFFSET(intra_dc_precision), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
+{"mb_threshold", "macroblock threshold", OFFSET(mb_threshold), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX},
+{"dc", "intra_dc_precision", OFFSET(intra_dc_precision), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"nssew", "nsse weight", OFFSET(nsse_weight), FF_OPT_TYPE_INT, 8, INT_MIN, INT_MAX, V|E},
 {"skip_top", NULL, OFFSET(skip_top), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|D},
 {"skip_bottom", NULL, OFFSET(skip_bottom), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|D},
@@ -705,14 +705,14 @@ static const AVOption options[]={
 {"level", NULL, OFFSET(level), FF_OPT_TYPE_INT, FF_LEVEL_UNKNOWN, INT_MIN, INT_MAX, V|A|E, "level"},
 {"unknown", NULL, 0, FF_OPT_TYPE_CONST, FF_LEVEL_UNKNOWN, INT_MIN, INT_MAX, V|A|E, "level"},
 {"lowres", NULL, OFFSET(lowres), FF_OPT_TYPE_INT, 0, 0, INT_MAX, V|D},
-{"frame_skip_threshold", NULL, OFFSET(frame_skip_threshold), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
-{"frame_skip_factor", NULL, OFFSET(frame_skip_factor), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
-{"frame_skip_exp", NULL, OFFSET(frame_skip_exp), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
+{"frame_skip_threshold", "frame skip threshold", OFFSET(frame_skip_threshold), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
+{"frame_skip_factor", "frame skip factor", OFFSET(frame_skip_factor), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
+{"frame_skip_exp", "frame skip exponent", OFFSET(frame_skip_exp), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"skipcmp", "frame skip compare function", OFFSET(frame_skip_cmp), FF_OPT_TYPE_INT, FF_CMP_DCTMAX, INT_MIN, INT_MAX, V|E, "cmp_func"},
 {"border_mask", NULL, OFFSET(border_masking), FF_OPT_TYPE_FLOAT, DEFAULT, FLT_MIN, FLT_MAX, V|E},
-{"mb_lmin", NULL, OFFSET(mb_lmin), FF_OPT_TYPE_INT, FF_QP2LAMBDA * 2, INT_MIN, INT_MAX, V|E},
-{"mb_lmax", NULL, OFFSET(mb_lmax), FF_OPT_TYPE_INT, FF_QP2LAMBDA * 31, INT_MIN, INT_MAX, V|E},
-{"me_penalty_compensation", NULL, OFFSET(me_penalty_compensation), FF_OPT_TYPE_INT, 256, INT_MIN, INT_MAX, V|E},
+{"mb_lmin", "min macroblock quantiser scale (VBR)", OFFSET(mb_lmin), FF_OPT_TYPE_INT, FF_QP2LAMBDA * 2, INT_MIN, INT_MAX, V|E},
+{"mb_lmax", "max macroblock quantiser scale (VBR)", OFFSET(mb_lmax), FF_OPT_TYPE_INT, FF_QP2LAMBDA * 31, INT_MIN, INT_MAX, V|E},
+{"me_penalty_compensation", "motion estimation bitrate penalty compensation", OFFSET(me_penalty_compensation), FF_OPT_TYPE_INT, 256, INT_MIN, INT_MAX, V|E},
 {"bidir_refine", NULL, OFFSET(bidir_refine), FF_OPT_TYPE_INT, DEFAULT, 0, 4, V|E},
 {"brd_scale", NULL, OFFSET(brd_scale), FF_OPT_TYPE_INT, DEFAULT, 0, 10, V|E},
 {"crf", NULL, OFFSET(crf), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},