On 12/04/2014 12:36 AM, wm4 wrote:
> On Wed, 3 Dec 2014 17:58:57 +0530
> anshul.ffm...@gmail.com wrote:
>
>> From: Nicolas George <geo...@nsup.org>
>>
>> ---
>> doc/indevs.texi | 9 ++++++
>> libavdevice/lavfi.c | 80
>> +++++++++++++++++++++++++++++++++++++++++++++++++----
>> 2 files changed, 84 insertions(+), 5 deletions(-)
>>
>> diff --git a/doc/indevs.texi b/doc/indevs.texi
>> index 5d2a308..f31e2e3 100644
>> --- a/doc/indevs.texi
>> +++ b/doc/indevs.texi
>> @@ -494,6 +494,9 @@ number starting from 0 corresponding to the mapped input
>> stream
>> generated by the device.
>> The first unlabelled output is automatically assigned to the "out0"
>> label, but all the others need to be specified explicitly.
>> +The suffix "+subcc" can be appended to the output label to create an extra
>> +stream with the closed captions packets attached to that output
>> +(experimental).
>>
>> If not specified defaults to the filename specified for the input
>> device.
>> @@ -541,6 +544,12 @@ Read an audio stream and a video stream and play it
>> back with
>> ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
>> @end example
>>
>> +@item
>> +Dump decoded frames to images and closed captions to a file (experimental):
>> +@example
>> +ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s
>> -c copy -f rawvideo subcc.bin
>> +@end example
>> +
>> @end itemize
>>
>> @section libcdio
>> diff --git a/libavdevice/lavfi.c b/libavdevice/lavfi.c
>> index 1398ece..bc45117 100644
>> --- a/libavdevice/lavfi.c
>> +++ b/libavdevice/lavfi.c
>> @@ -51,7 +51,10 @@ typedef struct {
>> int *sink_stream_map;
>> int *sink_eof;
>> int *stream_sink_map;
>> + int *sink_stream_subcc_map;
>> AVFrame *decoded_frame;
>> + int nb_sinks;
>> + AVPacket subcc_packet;
>> } LavfiContext;
>>
>> static int *create_all_formats(int n)
>> @@ -82,6 +85,7 @@ av_cold static int lavfi_read_close(AVFormatContext *avctx)
>> av_freep(&lavfi->sink_stream_map);
>> av_freep(&lavfi->sink_eof);
>> av_freep(&lavfi->stream_sink_map);
>> + av_freep(&lavfi->sink_stream_subcc_map);
>> av_freep(&lavfi->sinks);
>> avfilter_graph_free(&lavfi->graph);
>> av_frame_free(&lavfi->decoded_frame);
>> @@ -89,6 +93,27 @@ av_cold static int lavfi_read_close(AVFormatContext
>> *avctx)
>> return 0;
>> }
>>
>> +static int create_subcc_streams(AVFormatContext *avctx)
>> +{
>> + LavfiContext *lavfi = avctx->priv_data;
>> + AVStream *st;
>> + int stream_idx, sink_idx;
>> +
>> + for (stream_idx = 0; stream_idx < lavfi->nb_sinks; stream_idx++) {
>> + sink_idx = lavfi->stream_sink_map[stream_idx];
>> + if (lavfi->sink_stream_subcc_map[sink_idx]) {
>> + lavfi->sink_stream_subcc_map[sink_idx] = avctx->nb_streams;
>> + if (!(st = avformat_new_stream(avctx, NULL)))
>> + return AVERROR(ENOMEM);
>> + st->codec->codec_id = AV_CODEC_ID_EIA_608;
>> + st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
>> + } else {
>> + lavfi->sink_stream_subcc_map[sink_idx] = -1;
>> + }
>> + }
>> + return 0;
>> +}
>> +
>> av_cold static int lavfi_read_header(AVFormatContext *avctx)
>> {
>> LavfiContext *lavfi = avctx->priv_data;
>> @@ -153,6 +178,7 @@ av_cold static int lavfi_read_header(AVFormatContext
>> *avctx)
>>
>> /* count the outputs */
>> for (n = 0, inout = output_links; inout; n++, inout = inout->next);
>> + lavfi->nb_sinks = n;
>>
>> if (!(lavfi->sink_stream_map = av_malloc(sizeof(int) * n)))
>> FAIL(AVERROR(ENOMEM));
>> @@ -160,6 +186,8 @@ av_cold static int lavfi_read_header(AVFormatContext
>> *avctx)
>> FAIL(AVERROR(ENOMEM));
>> if (!(lavfi->stream_sink_map = av_malloc(sizeof(int) * n)))
>> FAIL(AVERROR(ENOMEM));
>> + if (!(lavfi->sink_stream_subcc_map = av_malloc(sizeof(int) * n)))
>> + FAIL(AVERROR(ENOMEM));
>>
>> for (i = 0; i < n; i++)
>> lavfi->stream_sink_map[i] = -1;
>> @@ -167,10 +195,10 @@ av_cold static int lavfi_read_header(AVFormatContext
>> *avctx)
>> /* parse the output link names - they need to be of the form out0,
>> out1, ...
>> * create a mapping between them and the streams */
>> for (i = 0, inout = output_links; inout; i++, inout = inout->next) {
>> - int stream_idx;
>> + int stream_idx, use_subcc = 0;
>> if (!strcmp(inout->name, "out"))
>> stream_idx = 0;
>> - else if (sscanf(inout->name, "out%d\n", &stream_idx) != 1) {
>> + else if (sscanf(inout->name, "out%d+subcc%n\n", &stream_idx,
>> &use_subcc) != 1) {
>> av_log(avctx, AV_LOG_ERROR,
>> "Invalid outpad name '%s'\n", inout->name);
>> FAIL(AVERROR(EINVAL));
>> @@ -192,6 +220,7 @@ av_cold static int lavfi_read_header(AVFormatContext
>> *avctx)
>> }
>> lavfi->sink_stream_map[i] = stream_idx;
>> lavfi->stream_sink_map[stream_idx] = i;
>> + lavfi->sink_stream_subcc_map[stream_idx] = !!use_subcc;
>> }
>>
>> /* for each open output create a corresponding stream */
>> @@ -203,7 +232,7 @@ av_cold static int lavfi_read_header(AVFormatContext
>> *avctx)
>> }
>>
>> /* create a sink for each output and connect them to the graph */
>> - lavfi->sinks = av_malloc_array(avctx->nb_streams,
>> sizeof(AVFilterContext *));
>> + lavfi->sinks = av_malloc_array(lavfi->nb_sinks, sizeof(AVFilterContext
>> *));
>> if (!lavfi->sinks)
>> FAIL(AVERROR(ENOMEM));
>>
>> @@ -267,7 +296,7 @@ av_cold static int lavfi_read_header(AVFormatContext
>> *avctx)
>> }
>>
>> /* fill each stream with the information in the corresponding sink */
>> - for (i = 0; i < avctx->nb_streams; i++) {
>> + for (i = 0; i < lavfi->nb_sinks; i++) {
>> AVFilterLink *link =
>> lavfi->sinks[lavfi->stream_sink_map[i]]->inputs[0];
>> AVStream *st = avctx->streams[i];
>> st->codec->codec_type = link->type;
>> @@ -298,6 +327,9 @@ av_cold static int lavfi_read_header(AVFormatContext
>> *avctx)
>> }
>> }
>>
>> + if ((ret = create_subcc_streams(avctx)) < 0)
>> + FAIL(ret);
>> +
>> if (!(lavfi->decoded_frame = av_frame_alloc()))
>> FAIL(AVERROR(ENOMEM));
>>
>> @@ -310,6 +342,30 @@ end:
>> return ret;
>> }
>>
>> +static int create_subcc_packet(AVFormatContext *avctx, AVFrame *frame,
>> + int sink_idx)
>> +{
>> + LavfiContext *lavfi = avctx->priv_data;
>> + AVFrameSideData *sd;
>> + int stream_idx, i, ret;
>> +
>> + if ((stream_idx = lavfi->sink_stream_subcc_map[sink_idx]) < 0)
>> + return 0;
>> + for (i = 0; i < frame->nb_side_data; i++)
>> + if (frame->side_data[i]->type == AV_FRAME_DATA_A53_CC)
>> + break;
>> + if (i >= frame->nb_side_data)
>> + return 0;
>> + sd = frame->side_data[i];
>> + if ((ret = av_new_packet(&lavfi->subcc_packet, sd->size)) < 0)
>> + return ret;
>> + memcpy(lavfi->subcc_packet.data, sd->data, sd->size);
>> + lavfi->subcc_packet.stream_index = stream_idx;
>> + lavfi->subcc_packet.pts = frame->pts;
>> + lavfi->subcc_packet.pos = av_frame_get_pkt_pos(frame);
>> + return 0;
>> +}
>> +
>> static int lavfi_read_packet(AVFormatContext *avctx, AVPacket *pkt)
>> {
>> LavfiContext *lavfi = avctx->priv_data;
>> @@ -321,9 +377,17 @@ static int lavfi_read_packet(AVFormatContext *avctx,
>> AVPacket *pkt)
>> int ret, i;
>> int size = 0;
>>
>> + if (lavfi->subcc_packet.size) {
>> + *pkt = lavfi->subcc_packet;
>> + av_init_packet(&lavfi->subcc_packet);
>> + lavfi->subcc_packet.size = 0;
>> + lavfi->subcc_packet.data = NULL;
>> + return pkt->size;
>> + }
>> +
>> /* iterate through all the graph sinks. Select the sink with the
>> * minimum PTS */
>> - for (i = 0; i < avctx->nb_streams; i++) {
>> + for (i = 0; i < lavfi->nb_sinks; i++) {
>> AVRational tb = lavfi->sinks[i]->inputs[0]->time_base;
>> double d;
>> int ret;
>> @@ -397,6 +461,12 @@ static int lavfi_read_packet(AVFormatContext *avctx,
>> AVPacket *pkt)
>> av_bprint_finalize(&meta_buf, NULL);
>> }
>>
>> + if ((ret = create_subcc_packet(avctx, frame, min_pts_sink_idx)) < 0) {
>> + av_frame_unref(frame);
>> + av_packet_unref(pkt);
>> + return ret;
>> + }
>> +
>> pkt->stream_index = stream_idx;
>> pkt->pts = frame->pts;
>> pkt->pos = av_frame_get_pkt_pos(frame);
>
> Why is this in libavdevice?
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
Dont know why its here, but this is most required part to extract cc
from h264 user data.
It may be because -f v4l2 is in device, Here input parameter is not
considered in normal way.
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