我有一个流媒体设备可以播放视频和音频。我试图捕获这些流并使用ffmpeg的HLS将它们保存为多个.ts文件。
因此，我成功地在单个.ts文件中捕获和保存流。看起来当我将输出文件发送到.m3u8时，ffmpeg会自动选择hls demuxer。但是，这样做我得到一个浮点异常。 这是我的简单代码......
static int ipcam_streaming_main_configure_input_parameters(const char *p_ifilename, AVFormatContext **ppx_ifmt_ctx)
{
AVStream *px_istream = NULL;
AVCodecContext *px_icodec_ctx = NULL;
int ret = -1;
unsigned int i = 0;
enum AVCodecID input_codec_id = AV_CODEC_ID_NONE;
AVCodec *p_decoder = NULL;
if (avformat_open_input(ppx_ifmt_ctx, p_ifilename, NULL, NULL) < 0)
{
printf("%s(): avformat_open_input() failed\n", __FUNCTION__);
}
else if (avformat_find_stream_info(*ppx_ifmt_ctx, NULL) < 0)
{
printf("%s(): avformat_find_stream_info() failed\n", __FUNCTION__);
}
else
{
/* find the input streams to be remuxed */
for (i = 0; i < (*ppx_ifmt_ctx)->nb_streams; i++)
{
/* get the stream, codec context for the stream */
px_istream = (*ppx_ifmt_ctx)->streams[i];
px_icodec_ctx = px_istream->codec;
if ((AVMEDIA_TYPE_VIDEO == px_icodec_ctx->codec_type)
|| (AVMEDIA_TYPE_AUDIO == px_icodec_ctx->codec_type))
{
/* get the codec_id for the audio/video stream */
input_codec_id = px_icodec_ctx->codec_id;
/* get the decoder for the input codec id */
p_decoder = avcodec_find_decoder(px_icodec_ctx->codec_id);
/* Open decoder for the input codec audio/video */
ret = avcodec_open2(px_icodec_ctx,
p_decoder,
NULL);
if (ret < 0)
{
printf("%s(): avcodec_open2() failed\n", __FUNCTION__);
}
else
{
printf("Input stream type <%d> with codec_id <%d> found and decoder opened\n", px_icodec_ctx->codec_type, input_codec_id);
}
}
}
}
/* dump the data into stdout */
av_dump_format(*ppx_ifmt_ctx, 0, p_ifilename, 0);
return ret;
}
static int ipcam_streaming_main_configure_output_parameters(const char *p_ofilename,
AVFormatContext *px_ifmt_ctx,
AVFormatContext **ppx_ofmt_ctx)
{
AVStream *px_ostream = NULL;
AVStream *px_istream = NULL;
AVCodecContext *px_dec_ctx = NULL;
AVCodecContext *px_enc_ctx = NULL;
int ret = -1;
unsigned int i = 0;
if ((NULL == p_ofilename) || (NULL == px_ifmt_ctx) || (NULL == ppx_ofmt_ctx))
{
printf("%s(): NULL arg(s) <%p, %p, %p>", __FUNCTION__, p_ofilename, px_ifmt_ctx, ppx_ofmt_ctx);
return -1;
}
/* remove the output file if already exists */
remove(p_ofilename);
/* allocate the output format context */
if (avformat_alloc_output_context2(ppx_ofmt_ctx, NULL, NULL, p_ofilename) < 0)
{
printf("%s(): avformat_alloc_output_context2() failed\n", __FUNCTION__);
}
else
{
for (i = 0; i < px_ifmt_ctx->nb_streams; i++)
{
if ((AVMEDIA_TYPE_VIDEO == px_ifmt_ctx->streams[i]->codec->codec_type)
|| (AVMEDIA_TYPE_AUDIO == px_ifmt_ctx->streams[i]->codec->codec_type))
{
printf("Stream <%d> is type <%d>: Adding to output stream\n", i, px_ifmt_ctx->streams[i]->codec->codec_type);
/* create a new output stream */
px_ostream = avformat_new_stream(*ppx_ofmt_ctx, NULL);
if (NULL == px_ostream)
{
printf("%s(): avformat_new_stream() failed\n", __FUNCTION__);
}
else
{
px_istream = px_ifmt_ctx->streams[i];
px_dec_ctx = px_istream->codec;
px_enc_ctx = px_ostream->codec;
/* Since, we do not need to encode the video stream, it is just remuxing
just copying the input codec context to output is sufficient */
ret = avcodec_copy_context((*ppx_ofmt_ctx)->streams[i]->codec,
px_ifmt_ctx->streams[i]->codec);
if ((*ppx_ofmt_ctx)->oformat->flags & AVFMT_GLOBALHEADER)
{
px_enc_ctx->flags |= CODEC_FLAG_GLOBAL_HEADER;
}
}
}
else
{
printf("Stream <%d> is Unknown: Ignore it \n", i);
}
}
/* dump the output media file into stdout */
av_dump_format(*ppx_ofmt_ctx, 0, p_ofilename, 1);
if (0 == ((*ppx_ofmt_ctx)->oformat->flags & AVFMT_NOFILE))
{
/* open the output media file so that we can write the data into it */
ret = avio_open(&(*ppx_ofmt_ctx)->pb, p_ofilename, AVIO_FLAG_WRITE);
if (ret < 0)
{
printf("%s(): avio_open() failed\n", __FUNCTION__);
}
else
{
/* init muxer, write output file header */
ret = avformat_write_header((*ppx_ofmt_ctx), NULL);
if (ret < 0)
{
printf("%s(): avformat_write_header() failed\n", __FUNCTION__);
}
}
}
}
return ret;
}
int main(int argnum, char **argv)
{
AVFormatContext *px_ifmt_ctx = NULL;
AVFormatContext *px_ofmt_ctx = NULL;
AVPacket packet = {0};
enum AVMediaType type = AVMEDIA_TYPE_UNKNOWN;
unsigned int stream_index = -1;
unsigned int i = 0;
int ret = -1;
if (argnum != 3)
{
printf("Please enough number of parameters\n");
return -1;
}
/* register all the services requred */
av_register_all();
avformat_network_init();
if (0 != ipcam_streaming_main_configure_input_parameters(argv[1],
&px_ifmt_ctx))
{
printf("%s(): ipcam_streaming_main_configure_iput_parameters() failed\n", __FUNCTION__);
}
else if (0 != ipcam_streaming_main_configure_output_parameters(argv[2],
px_ifmt_ctx,
&px_ofmt_ctx))
{
printf("%s(): ipcam_streaming_main_configure_output_parameters() failed\n", __FUNCTION__);
}
else
{
printf("Input and output configuration done successfully: Now reading packets\n");
while (true)
{
if ((ret = av_read_frame(px_ifmt_ctx, &packet)) < 0)
{
printf("av_read_frame() failed with error <%d>: Exit\n", ret);
break;
}
/* get the stream index and codec type of the packet read */
stream_index = packet.stream_index;
type = px_ifmt_ctx->streams[stream_index]->codec->codec_type;
/* remux only if the type is video, otherwise ignore it */
if ((AVMEDIA_TYPE_VIDEO == type)
|| (AVMEDIA_TYPE_AUDIO == type))
{
printf("Remuxing the stream type <%d>, frame with stream index <%d>\n", type, stream_index);
/* remux this frame without reencoding */
packet.dts = av_rescale_q_rnd(packet.dts,
px_ifmt_ctx->streams[stream_index]->time_base,
px_ofmt_ctx->streams[stream_index]->time_base,
AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX);
packet.pts = av_rescale_q_rnd(packet.pts,
px_ifmt_ctx->streams[stream_index]->time_base,
px_ofmt_ctx->streams[stream_index]->time_base,
AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX);
/* write the frame into the output media file */
ret = av_write_frame(px_ofmt_ctx, &packet);
if (ret < 0)
{
printf("Ignoring video packet stream index <%d>\n", packet.stream_index);
}
/* free the packet for next use */
av_free_packet(&packet);
}
else
{
printf("Ignoring stream index <%d>, type <%d>\n", packet.stream_index, type);
}
}
}
/* write the trailer */
av_write_trailer(px_ofmt_ctx);
av_free_packet(&packet);
for (i = 0; i < px_ifmt_ctx->nb_streams; i++)
{
/* close the input codec that has been opened */
avcodec_close(px_ifmt_ctx->streams[i]->codec);
if ((NULL != px_ofmt_ctx) && (px_ofmt_ctx->nb_streams > i) &&
(NULL != px_ofmt_ctx->streams[i]) && ( NULL != px_ofmt_ctx->streams[i]->codec))
{
/* close the output code */
avcodec_close(px_ofmt_ctx->streams[i]->codec);
}
}
/* close the input */
avformat_close_input(&px_ifmt_ctx);
if ((NULL != px_ofmt_ctx) && (0 == (px_ofmt_ctx->oformat->flags & AVFMT_NOFILE)))
{
/* close the output context */
avio_close(px_ofmt_ctx->pb);
}
/* free the output context */
avformat_free_context(px_ofmt_ctx);
return ret;
}
因此，如果我将输出文件名传递给.m3u8文件，则会产生浮点异常。