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, 59 insertions, 59 deletions

diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 50f9ccbe74..0ed56af1bd 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -1513,7 +1513,7 @@ static int matroska_parse_flac(AVFormatContext *s,
                     av_log(s, AV_LOG_WARNING,
                            "Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n");
                 } else
-                    st->codec->channel_layout = mask;
+                    st->codecpar->channel_layout = mask;
             }
             av_dict_free(&dict);
         }
@@ -1653,10 +1653,10 @@ static int matroska_parse_tracks(AVFormatContext *s)
             ffio_init_context(&b, track->codec_priv.data,
                               track->codec_priv.size,
                               0, NULL, NULL, NULL, NULL);
-            ret = ff_get_wav_header(s, &b, st->codec, track->codec_priv.size);
+            ret = ff_get_wav_header(s, &b, st->codecpar, track->codec_priv.size);
             if (ret < 0)
                 return ret;
-            codec_id         = st->codec->codec_id;
+            codec_id         = st->codecpar->codec_id;
             extradata_offset = FFMIN(track->codec_priv.size, 18);
         } else if (!strcmp(track->codec_id, "V_QUICKTIME") &&
                    (track->codec_priv.size >= 86)          &&
@@ -1775,15 +1775,15 @@ static int matroska_parse_tracks(AVFormatContext *s)
             if (!track->audio.buf)
                 return AVERROR(ENOMEM);
             if (codec_id == AV_CODEC_ID_RA_288) {
-                st->codec->block_align = track->audio.coded_framesize;
+                st->codecpar->block_align = track->audio.coded_framesize;
                 track->codec_priv.size = 0;
             } else {
                 if (codec_id == AV_CODEC_ID_SIPR && flavor < 4) {
                     const int sipr_bit_rate[4] = { 6504, 8496, 5000, 16000 };
                     track->audio.sub_packet_size = ff_sipr_subpk_size[flavor];
-                    st->codec->bit_rate          = sipr_bit_rate[flavor];
+                    st->codecpar->bit_rate          = sipr_bit_rate[flavor];
                 }
-                st->codec->block_align = track->audio.sub_packet_size;
+                st->codecpar->block_align = track->audio.sub_packet_size;
                 extradata_offset       = 78;
             }
         } else if (codec_id == AV_CODEC_ID_FLAC && track->codec_priv.size) {
@@ -1807,7 +1807,7 @@ static int matroska_parse_tracks(AVFormatContext *s)
                                           (AVRational){ 1, 1000000000 },
                                           st->time_base);
 
-        st->codec->codec_id = codec_id;
+        st->codecpar->codec_id = codec_id;
         st->start_time      = 0;
         if (strcmp(track->language, "und"))
             av_dict_set(&st->metadata, "language", track->language, 0);
@@ -1818,17 +1818,17 @@ static int matroska_parse_tracks(AVFormatContext *s)
         if (track->flag_forced)
             st->disposition |= AV_DISPOSITION_FORCED;
 
-        if (!st->codec->extradata) {
+        if (!st->codecpar->extradata) {
             if (extradata) {
-                st->codec->extradata      = extradata;
-                st->codec->extradata_size = extradata_size;
+                st->codecpar->extradata      = extradata;
+                st->codecpar->extradata_size = extradata_size;
             } else if (track->codec_priv.data && track->codec_priv.size > 0) {
-                st->codec->extradata = av_mallocz(track->codec_priv.size +
-                                                  AV_INPUT_BUFFER_PADDING_SIZE);
-                if (!st->codec->extradata)
+                st->codecpar->extradata = av_mallocz(track->codec_priv.size +
+                                                     AV_INPUT_BUFFER_PADDING_SIZE);
+                if (!st->codecpar->extradata)
                     return AVERROR(ENOMEM);
-                st->codec->extradata_size = track->codec_priv.size;
-                memcpy(st->codec->extradata,
+                st->codecpar->extradata_size = track->codec_priv.size;
+                memcpy(st->codecpar->extradata,
                        track->codec_priv.data + extradata_offset,
                        track->codec_priv.size);
             }
@@ -1838,21 +1838,21 @@ static int matroska_parse_tracks(AVFormatContext *s)
             int display_width_mul  = 1;
             int display_height_mul = 1;
 
-            st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
-            st->codec->codec_tag  = track->video.fourcc;
-            st->codec->width      = track->video.pixel_width;
-            st->codec->height     = track->video.pixel_height;
+            st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
+            st->codecpar->codec_tag  = track->video.fourcc;
+            st->codecpar->width      = track->video.pixel_width;
+            st->codecpar->height     = track->video.pixel_height;
 
             if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB)
                 mkv_stereo_mode_display_mul(track->video.stereo_mode, &display_width_mul, &display_height_mul);
 
             av_reduce(&st->sample_aspect_ratio.num,
                       &st->sample_aspect_ratio.den,
-                      st->codec->height * track->video.display_width  * display_width_mul,
-                      st->codec->width  * track->video.display_height * display_height_mul,
+                      st->codecpar->height * track->video.display_width  * display_width_mul,
+                      st->codecpar->width  * track->video.display_height * display_height_mul,
                       255);
-            if (st->codec->codec_id != AV_CODEC_ID_H264 &&
-                st->codec->codec_id != AV_CODEC_ID_HEVC)
+            if (st->codecpar->codec_id != AV_CODEC_ID_H264 &&
+                st->codecpar->codec_id != AV_CODEC_ID_HEVC)
                 st->need_parsing = AVSTREAM_PARSE_HEADERS;
             if (track->default_duration) {
                 av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
@@ -1866,16 +1866,16 @@ static int matroska_parse_tracks(AVFormatContext *s)
                     return ret;
             }
         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
-            st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
-            st->codec->sample_rate = track->audio.out_samplerate;
-            st->codec->channels    = track->audio.channels;
-            if (st->codec->codec_id != AV_CODEC_ID_AAC)
+            st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
+            st->codecpar->sample_rate = track->audio.out_samplerate;
+            st->codecpar->channels    = track->audio.channels;
+            if (st->codecpar->codec_id != AV_CODEC_ID_AAC)
                 st->need_parsing = AVSTREAM_PARSE_HEADERS;
-            if (st->codec->codec_id == AV_CODEC_ID_MP3)
+            if (st->codecpar->codec_id == AV_CODEC_ID_MP3)
                 st->need_parsing = AVSTREAM_PARSE_FULL;
         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
-            st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
-            if (st->codec->codec_id == AV_CODEC_ID_SSA)
+            st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
+            if (st->codecpar->codec_id == AV_CODEC_ID_SSA)
                 matroska->contains_ssa = 1;
         }
     }
@@ -1961,21 +1961,21 @@ static int matroska_read_header(AVFormatContext *s)
                 break;
             av_dict_set(&st->metadata, "filename", attachments[j].filename, 0);
             av_dict_set(&st->metadata, "mimetype", attachments[j].mime, 0);
-            st->codec->codec_id   = AV_CODEC_ID_NONE;
+            st->codecpar->codec_id   = AV_CODEC_ID_NONE;
 
             for (i = 0; ff_mkv_image_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
                 if (!strncmp(ff_mkv_image_mime_tags[i].str, attachments[j].mime,
                              strlen(ff_mkv_image_mime_tags[i].str))) {
-                    st->codec->codec_id = ff_mkv_image_mime_tags[i].id;
+                    st->codecpar->codec_id = ff_mkv_image_mime_tags[i].id;
                     break;
                 }
             }
 
             attachments[j].stream = st;
 
-            if (st->codec->codec_id != AV_CODEC_ID_NONE) {
-                st->disposition      |= AV_DISPOSITION_ATTACHED_PIC;
-                st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
+            if (st->codecpar->codec_id != AV_CODEC_ID_NONE) {
+                st->disposition         |= AV_DISPOSITION_ATTACHED_PIC;
+                st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
 
                 av_init_packet(&st->attached_pic);
                 if ((res = av_new_packet(&st->attached_pic, attachments[j].bin.size)) < 0)
@@ -1984,19 +1984,19 @@ static int matroska_read_header(AVFormatContext *s)
                 st->attached_pic.stream_index = st->index;
                 st->attached_pic.flags       |= AV_PKT_FLAG_KEY;
             } else {
-                st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
-                st->codec->extradata  = av_malloc(attachments[j].bin.size);
-                if (!st->codec->extradata)
+                st->codecpar->codec_type = AVMEDIA_TYPE_ATTACHMENT;
+                st->codecpar->extradata  = av_malloc(attachments[j].bin.size);
+                if (!st->codecpar->extradata)
                     break;
 
-                st->codec->extradata_size = attachments[j].bin.size;
-                memcpy(st->codec->extradata, attachments[j].bin.data,
+                st->codecpar->extradata_size = attachments[j].bin.size;
+                memcpy(st->codecpar->extradata, attachments[j].bin.data,
                        attachments[j].bin.size);
 
                 for (i = 0; ff_mkv_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
                     if (!strncmp(ff_mkv_mime_tags[i].str, attachments[j].mime,
                                 strlen(ff_mkv_mime_tags[i].str))) {
-                        st->codec->codec_id = ff_mkv_mime_tags[i].id;
+                        st->codecpar->codec_id = ff_mkv_mime_tags[i].id;
                         break;
                     }
                 }
@@ -2184,7 +2184,7 @@ static int matroska_parse_rm_audio(MatroskaDemuxContext *matroska,
                                    uint8_t *data, int size, uint64_t timecode,
                                    uint64_t duration, int64_t pos)
 {
-    int a = st->codec->block_align;
+    int a = st->codecpar->block_align;
     int sps = track->audio.sub_packet_size;
     int cfs = track->audio.coded_framesize;
     int h   = track->audio.sub_packet_h;
@@ -2195,7 +2195,7 @@ static int matroska_parse_rm_audio(MatroskaDemuxContext *matroska,
     if (!track->audio.pkt_cnt) {
         if (track->audio.sub_packet_cnt == 0)
             track->audio.buf_timecode = timecode;
-        if (st->codec->codec_id == AV_CODEC_ID_RA_288) {
+        if (st->codecpar->codec_id == AV_CODEC_ID_RA_288) {
             if (size < cfs * h / 2) {
                 av_log(matroska->ctx, AV_LOG_ERROR,
                        "Corrupt int4 RM-style audio packet size\n");
@@ -2204,7 +2204,7 @@ static int matroska_parse_rm_audio(MatroskaDemuxContext *matroska,
             for (x = 0; x < h / 2; x++)
                 memcpy(track->audio.buf + x * 2 * w + y * cfs,
                        data + x * cfs, cfs);
-        } else if (st->codec->codec_id == AV_CODEC_ID_SIPR) {
+        } else if (st->codecpar->codec_id == AV_CODEC_ID_SIPR) {
             if (size < w) {
                 av_log(matroska->ctx, AV_LOG_ERROR,
                        "Corrupt sipr RM-style audio packet size\n");
@@ -2224,7 +2224,7 @@ static int matroska_parse_rm_audio(MatroskaDemuxContext *matroska,
         }
 
         if (++track->audio.sub_packet_cnt >= h) {
-            if (st->codec->codec_id == AV_CODEC_ID_SIPR)
+            if (st->codecpar->codec_id == AV_CODEC_ID_SIPR)
                 ff_rm_reorder_sipr_data(track->audio.buf, h, w);
             track->audio.sub_packet_cnt = 0;
             track->audio.pkt_cnt        = h * w / a;
@@ -2266,10 +2266,10 @@ static int matroska_parse_wavpack(MatroskaTrack *track, uint8_t *src,
     uint16_t ver;
     int ret, offset = 0;
 
-    if (srclen < 12 || track->stream->codec->extradata_size < 2)
+    if (srclen < 12 || track->stream->codecpar->extradata_size < 2)
         return AVERROR_INVALIDDATA;
 
-    ver = AV_RL16(track->stream->codec->extradata);
+    ver = AV_RL16(track->stream->codecpar->extradata);
 
     samples = AV_RL32(src);
     src    += 4;
@@ -2353,7 +2353,7 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
             return res;
     }
 
-    if (st->codec->codec_id == AV_CODEC_ID_WAVPACK) {
+    if (st->codecpar->codec_id == AV_CODEC_ID_WAVPACK) {
         uint8_t *wv_data;
         res = matroska_parse_wavpack(track, pkt_data, &wv_data, &pkt_size);
         if (res < 0) {
@@ -2366,7 +2366,7 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
         pkt_data = wv_data;
     }
 
-    if (st->codec->codec_id == AV_CODEC_ID_PRORES)
+    if (st->codecpar->codec_id == AV_CODEC_ID_PRORES)
         offset = 8;
 
     pkt = av_mallocz(sizeof(AVPacket));
@@ -2381,7 +2381,7 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
         return AVERROR(ENOMEM);
     }
 
-    if (st->codec->codec_id == AV_CODEC_ID_PRORES) {
+    if (st->codecpar->codec_id == AV_CODEC_ID_PRORES) {
         uint8_t *buf = pkt->data;
         bytestream_put_be32(&buf, pkt_size);
         bytestream_put_be32(&buf, MKBETAG('i', 'c', 'p', 'f'));
@@ -2400,23 +2400,23 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
     else
         pkt->pts = timecode;
     pkt->pos = pos;
-    if (track->type != MATROSKA_TRACK_TYPE_SUBTITLE || st->codec->codec_id == AV_CODEC_ID_TEXT)
+    if (track->type != MATROSKA_TRACK_TYPE_SUBTITLE || st->codecpar->codec_id == AV_CODEC_ID_TEXT)
         pkt->duration = duration;
 #if FF_API_CONVERGENCE_DURATION
 FF_DISABLE_DEPRECATION_WARNINGS
-    if (st->codec->codec_id == AV_CODEC_ID_TEXT)
+    if (st->codecpar->codec_id == AV_CODEC_ID_TEXT)
         pkt->convergence_duration = duration;
 FF_ENABLE_DEPRECATION_WARNINGS
 #endif
 
-    if (st->codec->codec_id == AV_CODEC_ID_SSA)
+    if (st->codecpar->codec_id == AV_CODEC_ID_SSA)
         matroska_fix_ass_packet(matroska, pkt, duration);
 
     if (matroska->prev_pkt                                 &&
         timecode                         != AV_NOPTS_VALUE &&
         matroska->prev_pkt->pts          == timecode       &&
         matroska->prev_pkt->stream_index == st->index      &&
-        st->codec->codec_id == AV_CODEC_ID_SSA)
+        st->codecpar->codec_id == AV_CODEC_ID_SSA)
         matroska_merge_packets(matroska->prev_pkt, pkt);
     else {
         dynarray_add(&matroska->packets, &matroska->num_packets, pkt);
@@ -2510,11 +2510,11 @@ static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
             FFMAX(track->end_timecode, timecode + block_duration);
 
     for (n = 0; n < laces; n++) {
-        if ((st->codec->codec_id == AV_CODEC_ID_RA_288 ||
-             st->codec->codec_id == AV_CODEC_ID_COOK   ||
-             st->codec->codec_id == AV_CODEC_ID_SIPR   ||
-             st->codec->codec_id == AV_CODEC_ID_ATRAC3) &&
-            st->codec->block_align && track->audio.sub_packet_size) {
+        if ((st->codecpar->codec_id == AV_CODEC_ID_RA_288 ||
+             st->codecpar->codec_id == AV_CODEC_ID_COOK   ||
+             st->codecpar->codec_id == AV_CODEC_ID_SIPR   ||
+             st->codecpar->codec_id == AV_CODEC_ID_ATRAC3) &&
+            st->codecpar->block_align && track->audio.sub_packet_size) {
             res = matroska_parse_rm_audio(matroska, track, st, data,
                                           lace_size[n],
                                           timecode, duration, pos);