static int video_stream_idx = -1, audio_stream_idx = -1;
static AVFrame *frame = NULL;
-static AVPacket pkt;
+static AVPacket *pkt = NULL;
static int video_frame_count = 0;
static int audio_frame_count = 0;
-/* Enable or disable frame reference counting. You are not supposed to support
- * both paths in your application but pick the one most appropriate to your
- * needs. Look for the use of refcount in this example to see what are the
- * differences of API usage between them. */
-static int refcount = 0;
+static int output_video_frame(AVFrame *frame)
+{
+ if (frame->width != width || frame->height != height ||
+ frame->format != pix_fmt) {
+ /* To handle this change, one could call av_image_alloc again and
+ * decode the following frames into another rawvideo file. */
+ fprintf(stderr, "Error: Width, height and pixel format have to be "
+ "constant in a rawvideo file, but the width, height or "
+ "pixel format of the input video changed:\n"
+ "old: width = %d, height = %d, format = %s\n"
+ "new: width = %d, height = %d, format = %s\n",
+ width, height, av_get_pix_fmt_name(pix_fmt),
+ frame->width, frame->height,
+ av_get_pix_fmt_name(frame->format));
+ return -1;
+ }
+
+ printf("video_frame n:%d coded_n:%d\n",
+ video_frame_count++, frame->coded_picture_number);
+
+ /* copy decoded frame to destination buffer:
+ * this is required since rawvideo expects non aligned data */
+ av_image_copy(video_dst_data, video_dst_linesize,
+ (const uint8_t **)(frame->data), frame->linesize,
+ pix_fmt, width, height);
-static int decode_packet(int *got_frame, int cached)
+ /* write to rawvideo file */
+ fwrite(video_dst_data[0], 1, video_dst_bufsize, video_dst_file);
+ return 0;
+}
+
+static int output_audio_frame(AVFrame *frame)
+{
+ size_t unpadded_linesize = frame->nb_samples * av_get_bytes_per_sample(frame->format);
+ printf("audio_frame n:%d nb_samples:%d pts:%s\n",
+ audio_frame_count++, frame->nb_samples,
+ av_ts2timestr(frame->pts, &audio_dec_ctx->time_base));
+
+ /* Write the raw audio data samples of the first plane. This works
+ * fine for packed formats (e.g. AV_SAMPLE_FMT_S16). However,
+ * most audio decoders output planar audio, which uses a separate
+ * plane of audio samples for each channel (e.g. AV_SAMPLE_FMT_S16P).
+ * In other words, this code will write only the first audio channel
+ * in these cases.
+ * You should use libswresample or libavfilter to convert the frame
+ * to packed data. */
+ fwrite(frame->extended_data[0], 1, unpadded_linesize, audio_dst_file);
+
+ return 0;
+}
+
+static int decode_packet(AVCodecContext *dec, const AVPacket *pkt)
{
int ret = 0;
- int decoded = pkt.size;
- *got_frame = 0;
+ // submit the packet to the decoder
+ ret = avcodec_send_packet(dec, pkt);
+ if (ret < 0) {
+ fprintf(stderr, "Error submitting a packet for decoding (%s)\n", av_err2str(ret));
+ return ret;
+ }
- if (pkt.stream_index == video_stream_idx) {
- /* decode video frame */
- ret = avcodec_decode_video2(video_dec_ctx, frame, got_frame, &pkt);
+ // get all the available frames from the decoder
+ while (ret >= 0) {
+ ret = avcodec_receive_frame(dec, frame);
if (ret < 0) {
- fprintf(stderr, "Error decoding video frame (%s)\n", av_err2str(ret));
- return ret;
- }
+ // those two return values are special and mean there is no output
+ // frame available, but there were no errors during decoding
+ if (ret == AVERROR_EOF || ret == AVERROR(EAGAIN))
+ return 0;
- if (*got_frame) {
-
- if (frame->width != width || frame->height != height ||
- frame->format != pix_fmt) {
- /* To handle this change, one could call av_image_alloc again and
- * decode the following frames into another rawvideo file. */
- fprintf(stderr, "Error: Width, height and pixel format have to be "
- "constant in a rawvideo file, but the width, height or "
- "pixel format of the input video changed:\n"
- "old: width = %d, height = %d, format = %s\n"
- "new: width = %d, height = %d, format = %s\n",
- width, height, av_get_pix_fmt_name(pix_fmt),
- frame->width, frame->height,
- av_get_pix_fmt_name(frame->format));
- return -1;
- }
-
- printf("video_frame%s n:%d coded_n:%d\n",
- cached ? "(cached)" : "",
- video_frame_count++, frame->coded_picture_number);
-
- /* copy decoded frame to destination buffer:
- * this is required since rawvideo expects non aligned data */
- av_image_copy(video_dst_data, video_dst_linesize,
- (const uint8_t **)(frame->data), frame->linesize,
- pix_fmt, width, height);
-
- /* write to rawvideo file */
- fwrite(video_dst_data[0], 1, video_dst_bufsize, video_dst_file);
- }
- } else if (pkt.stream_index == audio_stream_idx) {
- /* decode audio frame */
- ret = avcodec_decode_audio4(audio_dec_ctx, frame, got_frame, &pkt);
- if (ret < 0) {
- fprintf(stderr, "Error decoding audio frame (%s)\n", av_err2str(ret));
+ fprintf(stderr, "Error during decoding (%s)\n", av_err2str(ret));
return ret;
}
- /* Some audio decoders decode only part of the packet, and have to be
- * called again with the remainder of the packet data.
- * Sample: fate-suite/lossless-audio/luckynight-partial.shn
- * Also, some decoders might over-read the packet. */
- decoded = FFMIN(ret, pkt.size);
-
- if (*got_frame) {
- size_t unpadded_linesize = frame->nb_samples * av_get_bytes_per_sample(frame->format);
- printf("audio_frame%s n:%d nb_samples:%d pts:%s\n",
- cached ? "(cached)" : "",
- audio_frame_count++, frame->nb_samples,
- av_ts2timestr(frame->pts, &audio_dec_ctx->time_base));
-
- /* Write the raw audio data samples of the first plane. This works
- * fine for packed formats (e.g. AV_SAMPLE_FMT_S16). However,
- * most audio decoders output planar audio, which uses a separate
- * plane of audio samples for each channel (e.g. AV_SAMPLE_FMT_S16P).
- * In other words, this code will write only the first audio channel
- * in these cases.
- * You should use libswresample or libavfilter to convert the frame
- * to packed data. */
- fwrite(frame->extended_data[0], 1, unpadded_linesize, audio_dst_file);
- }
- }
- /* If we use frame reference counting, we own the data and need
- * to de-reference it when we don't use it anymore */
- if (*got_frame && refcount)
+ // write the frame data to output file
+ if (dec->codec->type == AVMEDIA_TYPE_VIDEO)
+ ret = output_video_frame(frame);
+ else
+ ret = output_audio_frame(frame);
+
av_frame_unref(frame);
+ if (ret < 0)
+ return ret;
+ }
- return decoded;
+ return 0;
}
static int open_codec_context(int *stream_idx,
{
int ret, stream_index;
AVStream *st;
- AVCodec *dec = NULL;
+ const AVCodec *dec = NULL;
AVDictionary *opts = NULL;
ret = av_find_best_stream(fmt_ctx, type, -1, -1, NULL, 0);
return ret;
}
- /* Init the decoders, with or without reference counting */
- av_dict_set(&opts, "refcounted_frames", refcount ? "1" : "0", 0);
+ /* Init the decoders */
if ((ret = avcodec_open2(*dec_ctx, dec, &opts)) < 0) {
fprintf(stderr, "Failed to open %s codec\n",
av_get_media_type_string(type));
int main (int argc, char **argv)
{
- int ret = 0, got_frame;
+ int ret = 0;
- if (argc != 4 && argc != 5) {
- fprintf(stderr, "usage: %s [-refcount] input_file video_output_file audio_output_file\n"
+ if (argc != 4) {
+ fprintf(stderr, "usage: %s input_file video_output_file audio_output_file\n"
"API example program to show how to read frames from an input file.\n"
"This program reads frames from a file, decodes them, and writes decoded\n"
"video frames to a rawvideo file named video_output_file, and decoded\n"
- "audio frames to a rawaudio file named audio_output_file.\n\n"
- "If the -refcount option is specified, the program use the\n"
- "reference counting frame system which allows keeping a copy of\n"
- "the data for longer than one decode call.\n"
- "\n", argv[0]);
+ "audio frames to a rawaudio file named audio_output_file.\n",
+ argv[0]);
exit(1);
}
- if (argc == 5 && !strcmp(argv[1], "-refcount")) {
- refcount = 1;
- argv++;
- }
src_filename = argv[1];
video_dst_filename = argv[2];
audio_dst_filename = argv[3];
goto end;
}
- /* initialize packet, set data to NULL, let the demuxer fill it */
- av_init_packet(&pkt);
- pkt.data = NULL;
- pkt.size = 0;
+ pkt = av_packet_alloc();
+ if (!pkt) {
+ fprintf(stderr, "Could not allocate packet\n");
+ ret = AVERROR(ENOMEM);
+ goto end;
+ }
if (video_stream)
printf("Demuxing video from file '%s' into '%s'\n", src_filename, video_dst_filename);
printf("Demuxing audio from file '%s' into '%s'\n", src_filename, audio_dst_filename);
/* read frames from the file */
- while (av_read_frame(fmt_ctx, &pkt) >= 0) {
- AVPacket orig_pkt = pkt;
- do {
- ret = decode_packet(&got_frame, 0);
- if (ret < 0)
- break;
- pkt.data += ret;
- pkt.size -= ret;
- } while (pkt.size > 0);
- av_packet_unref(&orig_pkt);
+ while (av_read_frame(fmt_ctx, pkt) >= 0) {
+ // check if the packet belongs to a stream we are interested in, otherwise
+ // skip it
+ if (pkt->stream_index == video_stream_idx)
+ ret = decode_packet(video_dec_ctx, pkt);
+ else if (pkt->stream_index == audio_stream_idx)
+ ret = decode_packet(audio_dec_ctx, pkt);
+ av_packet_unref(pkt);
+ if (ret < 0)
+ break;
}
- /* flush cached frames */
- pkt.data = NULL;
- pkt.size = 0;
- do {
- decode_packet(&got_frame, 1);
- } while (got_frame);
+ /* flush the decoders */
+ if (video_dec_ctx)
+ decode_packet(video_dec_ctx, NULL);
+ if (audio_dec_ctx)
+ decode_packet(audio_dec_ctx, NULL);
printf("Demuxing succeeded.\n");
fclose(video_dst_file);
if (audio_dst_file)
fclose(audio_dst_file);
+ av_packet_free(&pkt);
av_frame_free(&frame);
av_free(video_dst_data[0]);
projects / ffmpeg / blobdiff