int attribute_align_arg avcodec_open(AVCodecContext *avctx, AVCodec *codec) { int ret= -1; /* If there is a user-supplied mutex locking routine, call it. */ if (ff_lockmgr_cb) { if ((*ff_lockmgr_cb)(&codec_mutex, AV_LOCK_OBTAIN)) return -1; } entangled_thread_counter++; if(entangled_thread_counter != 1){ av_log(avctx, AV_LOG_ERROR, "insufficient thread locking around avcodec_open/close()\n"); goto end; } if(avctx->codec || !codec) goto end; if (codec->priv_data_size > 0) { avctx->priv_data = av_mallocz(codec->priv_data_size); if (!avctx->priv_data) { ret = AVERROR(ENOMEM); goto end; } } else { avctx->priv_data = NULL; } if(avctx->coded_width && avctx->coded_height) avcodec_set_dimensions(avctx, avctx->coded_width, avctx->coded_height); else if(avctx->width && avctx->height) avcodec_set_dimensions(avctx, avctx->width, avctx->height); #define SANE_NB_CHANNELS 128U if (((avctx->coded_width || avctx->coded_height) && av_image_check_size(avctx->coded_width, avctx->coded_height, 0, avctx)) || avctx->channels > SANE_NB_CHANNELS) { ret = AVERROR(EINVAL); goto free_and_end; } avctx->codec = codec; if ((avctx->codec_type == AVMEDIA_TYPE_UNKNOWN || avctx->codec_type == codec->type) && avctx->codec_id == CODEC_ID_NONE) { avctx->codec_type = codec->type; avctx->codec_id = codec->id; } if(avctx->codec_id != codec->id || avctx->codec_type != codec->type){ av_log(avctx, AV_LOG_ERROR, "codec type or id mismatches\n"); goto free_and_end; } avctx->frame_number = 0; if (avctx->codec->max_lowres < avctx->lowres) { av_log(avctx, AV_LOG_ERROR, "The maximum value for lowres supported by the decoder is %d\n", avctx->codec->max_lowres); goto free_and_end; } if(avctx->codec->init){ ret = avctx->codec->init(avctx); if (ret < 0) { goto free_and_end; } } ret=0; end: entangled_thread_counter--; /* Release any user-supplied mutex. */ if (ff_lockmgr_cb) { (*ff_lockmgr_cb)(&codec_mutex, AV_LOCK_RELEASE); } return ret; free_and_end: av_freep(&avctx->priv_data); avctx->codec= NULL; goto end; }