avconv: do not use the stream codec context for encoding

avconv.h

@@ -314,6 +314,7 @@ typedef struct OutputStream {
     /* dts of the last packet sent to the muxer */
     int64_t last_mux_dts;
     AVBitStreamFilterContext *bitstream_filters;
+    AVCodecContext *enc_ctx;
     AVCodec *enc;
     int64_t max_frames;
     AVFrame *filtered_frame;

avconv_filter.c

@@ -39,8 +39,8 @@
 #define DEF_CHOOSE_FORMAT(type, var, supported_list, none, get_name)           \
 static char *choose_ ## var ## s(OutputStream *ost)                            \
 {                                                                              \
-    if (ost->st->codec->var != none) {                                         \
-        get_name(ost->st->codec->var);                                         \
+    if (ost->enc_ctx->var != none) {                                           \
+        get_name(ost->enc_ctx->var);                                           \
         return av_strdup(name);                                                \
     } else if (ost->enc && ost->enc->supported_list) {                         \
         const type *p;                                                         \
@@ -231,7 +231,7 @@ static int configure_output_video_filter(FilterGraph *fg, OutputFilter *ofilter,
     char *pix_fmts;
     OutputStream *ost = ofilter->ost;
     OutputFile    *of = output_files[ost->file_index];
-    AVCodecContext *codec = ost->st->codec;
+    AVCodecContext *codec = ost->enc_ctx;
     AVFilterContext *last_filter = out->filter_ctx;
     int pad_idx = out->pad_idx;
     int ret;
@@ -319,7 +319,7 @@ static int configure_output_audio_filter(FilterGraph *fg, OutputFilter *ofilter,
 {
     OutputStream *ost = ofilter->ost;
     OutputFile    *of = output_files[ost->file_index];
-    AVCodecContext *codec  = ost->st->codec;
+    AVCodecContext *codec  = ost->enc_ctx;
     AVFilterContext *last_filter = out->filter_ctx;
     int pad_idx = out->pad_idx;
     char *sample_fmts, *sample_rates, *channel_layouts;

avconv_opt.c

@@ -905,6 +905,14 @@ static OutputStream *new_output_stream(OptionsContext *o, AVFormatContext *oc, e
     ost->st         = st;
     st->codec->codec_type = type;
     choose_encoder(o, oc, ost);
+
+    ost->enc_ctx = avcodec_alloc_context3(ost->enc);
+    if (!ost->enc_ctx) {
+        av_log(NULL, AV_LOG_ERROR, "Error allocating the encoding context.\n");
+        exit_program(1);
+    }
+    ost->enc_ctx->codec_type = type;
+
     if (ost->enc) {
         AVIOContext *s = NULL;
         char *buf = NULL, *arg = NULL, *preset = NULL;
@@ -939,9 +947,6 @@ static OutputStream *new_output_stream(OptionsContext *o, AVFormatContext *oc, e
         ost->encoder_opts = filter_codec_opts(o->g->codec_opts, AV_CODEC_ID_NONE, oc, st, NULL);
     }
 
-    avcodec_get_context_defaults3(st->codec, ost->enc);
-    st->codec->codec_type = type; // XXX hack, avcodec_get_context_defaults2() sets type to unknown for stream copy
-
     ost->max_frames = INT64_MAX;
     MATCH_PER_STREAM_OPT(max_frames, i64, ost->max_frames, oc, st);
 
@@ -967,17 +972,17 @@ static OutputStream *new_output_stream(OptionsContext *o, AVFormatContext *oc, e
         uint32_t tag = strtol(codec_tag, &next, 0);
         if (*next)
             tag = AV_RL32(codec_tag);
-        st->codec->codec_tag = tag;
+        ost->enc_ctx->codec_tag = tag;
     }
 
     MATCH_PER_STREAM_OPT(qscale, dbl, qscale, oc, st);
     if (qscale >= 0) {
-        st->codec->flags |= CODEC_FLAG_QSCALE;
-        st->codec->global_quality = FF_QP2LAMBDA * qscale;
+        ost->enc_ctx->flags |= CODEC_FLAG_QSCALE;
+        ost->enc_ctx->global_quality = FF_QP2LAMBDA * qscale;
     }
 
     if (oc->oformat->flags & AVFMT_GLOBALHEADER)
-        st->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
+        ost->enc_ctx->flags |= CODEC_FLAG_GLOBAL_HEADER;
 
     av_opt_get_int(o->g->sws_opts, "sws_flags", 0, &ost->sws_flags);
 
@@ -1068,7 +1073,7 @@ static OutputStream *new_video_stream(OptionsContext *o, AVFormatContext *oc)
 
     ost = new_output_stream(o, oc, AVMEDIA_TYPE_VIDEO);
     st  = ost->st;
-    video_enc = st->codec;
+    video_enc = ost->enc_ctx;
 
     MATCH_PER_STREAM_OPT(frame_aspect_ratios, str, frame_aspect_ratio, oc, st);
     if (frame_aspect_ratio)
@@ -1189,7 +1194,7 @@ static OutputStream *new_audio_stream(OptionsContext *o, AVFormatContext *oc)
     ost = new_output_stream(o, oc, AVMEDIA_TYPE_AUDIO);
     st  = ost->st;
 
-    audio_enc = st->codec;
+    audio_enc = ost->enc_ctx;
     audio_enc->codec_type = AVMEDIA_TYPE_AUDIO;
 
     if (!ost->stream_copy) {
@@ -1237,13 +1242,11 @@ static OutputStream *new_attachment_stream(OptionsContext *o, AVFormatContext *o
 
 static OutputStream *new_subtitle_stream(OptionsContext *o, AVFormatContext *oc)
 {
-    AVStream *st;
     OutputStream *ost;
     AVCodecContext *subtitle_enc;
 
     ost = new_output_stream(o, oc, AVMEDIA_TYPE_SUBTITLE);
-    st  = ost->st;
-    subtitle_enc = st->codec;
+    subtitle_enc = ost->enc_ctx;
 
     subtitle_enc->codec_type = AVMEDIA_TYPE_SUBTITLE;