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, 46 insertions, 46 deletions

diff --git a/libavformat/mxfenc.c b/libavformat/mxfenc.c
index 3a3008b9d3..c5d2de0a4d 100644
--- a/libavformat/mxfenc.c
+++ b/libavformat/mxfenc.c
@@ -611,7 +611,7 @@ static void mxf_write_common_fields(AVFormatContext *s, AVStream *st)
     if (st == mxf->timecode_track)
         avio_write(pb, smpte_12m_timecode_track_data_ul, 16);
     else {
-        const MXFCodecUL *data_def_ul = mxf_get_data_definition_ul(st->codec->codec_type);
+        const MXFCodecUL *data_def_ul = mxf_get_data_definition_ul(st->codecpar->codec_type);
         avio_write(pb, data_def_ul->uid, 16);
     }
 
@@ -782,27 +782,27 @@ static void mxf_write_cdci_common(AVFormatContext *s, AVStream *st, const UID ke
 {
     MXFStreamContext *sc = st->priv_data;
     AVIOContext *pb = s->pb;
-    int stored_height = (st->codec->height+15)/16*16;
+    int stored_height = (st->codecpar->height+15)/16*16;
     int display_height;
     int f1, f2;
 
     mxf_write_generic_desc(s, st, key, size+8+8+8+8+8+8+5+16+sc->interlaced*4+12+20);
 
     mxf_write_local_tag(pb, 4, 0x3203);
-    avio_wb32(pb, st->codec->width);
+    avio_wb32(pb, st->codecpar->width);
 
     mxf_write_local_tag(pb, 4, 0x3202);
     avio_wb32(pb, stored_height>>sc->interlaced);
 
     mxf_write_local_tag(pb, 4, 0x3209);
-    avio_wb32(pb, st->codec->width);
+    avio_wb32(pb, st->codecpar->width);
 
-    if (st->codec->height == 608) // PAL + VBI
+    if (st->codecpar->height == 608) // PAL + VBI
         display_height = 576;
-    else if (st->codec->height == 512)  // NTSC + VBI
+    else if (st->codecpar->height == 512)  // NTSC + VBI
         display_height = 486;
     else
-        display_height = st->codec->height;
+        display_height = st->codecpar->height;
 
     mxf_write_local_tag(pb, 4, 0x3208);
     avio_wb32(pb, display_height>>sc->interlaced);
@@ -820,7 +820,7 @@ static void mxf_write_cdci_common(AVFormatContext *s, AVStream *st, const UID ke
     avio_w8(pb, sc->interlaced);
 
     // video line map
-    switch (st->codec->height) {
+    switch (st->codecpar->height) {
     case  576: f1 = 23; f2 = 336; break;
     case  608: f1 =  7; f2 = 320; break;
     case  480: f1 = 20; f2 = 283; break;
@@ -858,17 +858,17 @@ static void mxf_write_cdci_desc(AVFormatContext *s, AVStream *st)
 static void mxf_write_mpegvideo_desc(AVFormatContext *s, AVStream *st)
 {
     AVIOContext *pb = s->pb;
-    int profile_and_level = (st->codec->profile<<4) | st->codec->level;
+    int profile_and_level = (st->codecpar->profile<<4) | st->codecpar->level;
 
     mxf_write_cdci_common(s, st, mxf_mpegvideo_descriptor_key, 8+5);
 
     // bit rate
     mxf_write_local_tag(pb, 4, 0x8000);
-    avio_wb32(pb, st->codec->bit_rate);
+    avio_wb32(pb, st->codecpar->bit_rate);
 
     // profile and level
     mxf_write_local_tag(pb, 1, 0x8007);
-    if (!st->codec->profile)
+    if (!st->codecpar->profile)
         profile_and_level |= 0x80; // escape bit
     avio_w8(pb, profile_and_level);
 }
@@ -885,14 +885,14 @@ static void mxf_write_generic_sound_common(AVFormatContext *s, AVStream *st, con
 
     // write audio sampling rate
     mxf_write_local_tag(pb, 8, 0x3D03);
-    avio_wb32(pb, st->codec->sample_rate);
+    avio_wb32(pb, st->codecpar->sample_rate);
     avio_wb32(pb, 1);
 
     mxf_write_local_tag(pb, 4, 0x3D07);
-    avio_wb32(pb, st->codec->channels);
+    avio_wb32(pb, st->codecpar->channels);
 
     mxf_write_local_tag(pb, 4, 0x3D01);
-    avio_wb32(pb, av_get_bits_per_sample(st->codec->codec_id));
+    avio_wb32(pb, av_get_bits_per_sample(st->codecpar->codec_id));
 }
 
 static void mxf_write_wav_common(AVFormatContext *s, AVStream *st, const UID key, unsigned size)
@@ -902,11 +902,11 @@ static void mxf_write_wav_common(AVFormatContext *s, AVStream *st, const UID key
     mxf_write_generic_sound_common(s, st, key, size+6+8);
 
     mxf_write_local_tag(pb, 2, 0x3D0A);
-    avio_wb16(pb, st->codec->block_align);
+    avio_wb16(pb, st->codecpar->block_align);
 
     // avg bytes per sec
     mxf_write_local_tag(pb, 4, 0x3D09);
-    avio_wb32(pb, st->codec->block_align*st->codec->sample_rate);
+    avio_wb32(pb, st->codecpar->block_align*st->codecpar->sample_rate);
 }
 
 static void mxf_write_wav_desc(AVFormatContext *s, AVStream *st)
@@ -1293,21 +1293,21 @@ static const UID mxf_mpeg2_codec_uls[] = {
     { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x03,0x04,0x01,0x02,0x02,0x01,0x05,0x03,0x00 }, // MP@H-14 Long GOP
 };
 
-static const UID *mxf_get_mpeg2_codec_ul(AVCodecContext *avctx)
+static const UID *mxf_get_mpeg2_codec_ul(AVCodecParameters *par)
 {
     int long_gop = 1;
 
-    if (avctx->profile == 4) { // Main
-        if (avctx->level == 8) // Main
+    if (par->profile == 4) { // Main
+        if (par->level == 8) // Main
             return &mxf_mpeg2_codec_uls[0+long_gop];
-        else if (avctx->level == 4) // High
+        else if (par->level == 4) // High
             return &mxf_mpeg2_codec_uls[4+long_gop];
-        else if (avctx->level == 6) // High 14
+        else if (par->level == 6) // High 14
             return &mxf_mpeg2_codec_uls[8+long_gop];
-    } else if (avctx->profile == 0) { // 422
-        if (avctx->level == 5) // Main
+    } else if (par->profile == 0) { // 422
+        if (par->level == 5) // Main
             return &mxf_mpeg2_codec_uls[2+long_gop];
-        else if (avctx->level == 2) // High
+        else if (par->level == 2) // High
             return &mxf_mpeg2_codec_uls[6+long_gop];
     }
     return NULL;
@@ -1325,8 +1325,8 @@ static int mxf_parse_mpeg2_frame(AVFormatContext *s, AVStream *st,
         c = (c<<8) + pkt->data[i];
         if (c == 0x1b5) {
             if ((pkt->data[i+1] & 0xf0) == 0x10) { // seq ext
-                st->codec->profile = pkt->data[i+1] & 0x07;
-                st->codec->level   = pkt->data[i+2] >> 4;
+                st->codecpar->profile = pkt->data[i+1] & 0x07;
+                st->codecpar->level   = pkt->data[i+2] >> 4;
             } else if (i + 5 < pkt->size && (pkt->data[i+1] & 0xf0) == 0x80) { // pict coding ext
                 sc->interlaced = !(pkt->data[i+5] & 0x80); // progressive frame
                 break;
@@ -1360,7 +1360,7 @@ static int mxf_parse_mpeg2_frame(AVFormatContext *s, AVStream *st,
             case 4:  sc->aspect_ratio = (AVRational){221,100}; break;
             default:
                 av_reduce(&sc->aspect_ratio.num, &sc->aspect_ratio.den,
-                          st->codec->width, st->codec->height, 1024*1024);
+                          st->codecpar->width, st->codecpar->height, 1024*1024);
             }
         } else if (c == 0x100) { // pic
             int pict_type = (pkt->data[i+2]>>3) & 0x07;
@@ -1381,7 +1381,7 @@ static int mxf_parse_mpeg2_frame(AVFormatContext *s, AVStream *st,
         }
     }
     if (s->oformat != &ff_mxf_d10_muxer)
-        sc->codec_ul = mxf_get_mpeg2_codec_ul(st->codec);
+        sc->codec_ul = mxf_get_mpeg2_codec_ul(st->codecpar);
     return !!sc->codec_ul;
 }
 
@@ -1430,7 +1430,7 @@ static int mxf_write_header(AVFormatContext *s)
             return AVERROR(ENOMEM);
         st->priv_data = sc;
 
-        if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
+        if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
             if (i != 0) {
                 av_log(s, AV_LOG_ERROR, "video stream must be first track\n");
                 return -1;
@@ -1450,13 +1450,13 @@ static int mxf_write_header(AVFormatContext *s)
             }
             avpriv_set_pts_info(st, 64, mxf->time_base.num, mxf->time_base.den);
             if (s->oformat == &ff_mxf_d10_muxer) {
-                if (st->codec->bit_rate == 50000000)
+                if (st->codecpar->bit_rate == 50000000)
                     if (mxf->time_base.den == 25) sc->index = 3;
                     else                          sc->index = 5;
-                else if (st->codec->bit_rate == 40000000)
+                else if (st->codecpar->bit_rate == 40000000)
                     if (mxf->time_base.den == 25) sc->index = 7;
                     else                          sc->index = 9;
-                else if (st->codec->bit_rate == 30000000)
+                else if (st->codecpar->bit_rate == 30000000)
                     if (mxf->time_base.den == 25) sc->index = 11;
                     else                          sc->index = 13;
                 else {
@@ -1465,25 +1465,25 @@ static int mxf_write_header(AVFormatContext *s)
                 }
 
                 mxf->edit_unit_byte_count = KAG_SIZE; // system element
-                mxf->edit_unit_byte_count += 16 + 4 + (uint64_t)st->codec->bit_rate *
+                mxf->edit_unit_byte_count += 16 + 4 + (uint64_t)st->codecpar->bit_rate *
                     mxf->time_base.num / (8*mxf->time_base.den);
                 mxf->edit_unit_byte_count += klv_fill_size(mxf->edit_unit_byte_count);
                 mxf->edit_unit_byte_count += 16 + 4 + 4 + samples_per_frame[0]*8*4;
                 mxf->edit_unit_byte_count += klv_fill_size(mxf->edit_unit_byte_count);
             }
-        } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
-            if (st->codec->sample_rate != 48000) {
+        } else if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
+            if (st->codecpar->sample_rate != 48000) {
                 av_log(s, AV_LOG_ERROR, "only 48khz is implemented\n");
                 return -1;
             }
-            avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
+            avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
             if (s->oformat == &ff_mxf_d10_muxer) {
                 if (st->index != 1) {
                     av_log(s, AV_LOG_ERROR, "MXF D-10 only support one audio track\n");
                     return -1;
                 }
-                if (st->codec->codec_id != AV_CODEC_ID_PCM_S16LE &&
-                    st->codec->codec_id != AV_CODEC_ID_PCM_S24LE) {
+                if (st->codecpar->codec_id != AV_CODEC_ID_PCM_S16LE &&
+                    st->codecpar->codec_id != AV_CODEC_ID_PCM_S24LE) {
                     av_log(s, AV_LOG_ERROR, "MXF D-10 only support 16 or 24 bits le audio\n");
                 }
                 sc->index = ((MXFStreamContext*)s->streams[0]->priv_data)->index + 1;
@@ -1492,7 +1492,7 @@ static int mxf_write_header(AVFormatContext *s)
         }
 
         if (!sc->index) {
-            sc->index = mxf_get_essence_container_ul_index(st->codec->codec_id);
+            sc->index = mxf_get_essence_container_ul_index(st->codecpar->codec_id);
             if (sc->index == -1) {
                 av_log(s, AV_LOG_ERROR, "track %d: could not find essence container ul, "
                        "codec not currently supported in container\n", i);
@@ -1615,7 +1615,7 @@ static void mxf_write_d10_video_packet(AVFormatContext *s, AVStream *st, AVPacke
 {
     MXFContext *mxf = s->priv_data;
     AVIOContext *pb = s->pb;
-    int packet_size = (uint64_t)st->codec->bit_rate*mxf->time_base.num /
+    int packet_size = (uint64_t)st->codecpar->bit_rate*mxf->time_base.num /
         (8*mxf->time_base.den); // frame size
     int pad;
 
@@ -1645,7 +1645,7 @@ static void mxf_write_d10_audio_packet(AVFormatContext *s, AVStream *st, AVPacke
 {
     MXFContext *mxf = s->priv_data;
     AVIOContext *pb = s->pb;
-    int frame_size = pkt->size / st->codec->block_align;
+    int frame_size = pkt->size / st->codecpar->block_align;
     uint8_t *samples = pkt->data;
     uint8_t *end = pkt->data + pkt->size;
     int i;
@@ -1654,12 +1654,12 @@ static void mxf_write_d10_audio_packet(AVFormatContext *s, AVStream *st, AVPacke
 
     avio_w8(pb, (frame_size == 1920 ? 0 : (mxf->edit_units_count-1) % 5 + 1));
     avio_wl16(pb, frame_size);
-    avio_w8(pb, (1<<st->codec->channels)-1);
+    avio_w8(pb, (1<<st->codecpar->channels)-1);
 
     while (samples < end) {
-        for (i = 0; i < st->codec->channels; i++) {
+        for (i = 0; i < st->codecpar->channels; i++) {
             uint32_t sample;
-            if (st->codec->codec_id == AV_CODEC_ID_PCM_S24LE) {
+            if (st->codecpar->codec_id == AV_CODEC_ID_PCM_S24LE) {
                 sample = AV_RL24(samples)<< 4;
                 samples += 3;
             } else {
@@ -1691,7 +1691,7 @@ static int mxf_write_packet(AVFormatContext *s, AVPacket *pkt)
         }
     }
 
-    if (st->codec->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
+    if (st->codecpar->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
         if (!mxf_parse_mpeg2_frame(s, st, pkt, &ie)) {
             av_log(s, AV_LOG_ERROR, "could not get mpeg2 profile and level\n");
             return -1;
@@ -1740,7 +1740,7 @@ static int mxf_write_packet(AVFormatContext *s, AVPacket *pkt)
     mxf_write_klv_fill(s);
     avio_write(pb, sc->track_essence_element_key, 16); // write key
     if (s->oformat == &ff_mxf_d10_muxer) {
-        if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO)
+        if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
             mxf_write_d10_video_packet(s, st, pkt);
         else
             mxf_write_d10_audio_packet(s, st, pkt);