[FFmpeg-devel] Mono ADPCM for EA WVE Files / Fix Framerate
Peter Ross
pross at xvid.org
Sat Jul 20 02:54:37 EEST 2024
On Fri, Jul 19, 2024 at 07:34:18AM -0400, redacted redacted wrote:
> Hello there,
>
> The Sims 1: Unleashed makes use of WVE files for its intro videos.
> Two of the files for the game use Mono ADPCM audio instead of Stereo.
> However, FFmpeg's ADPCM_EA codec always expects the files to be in Stereo.
can you post a sample file somewhere
> In addition, they're supposed to play at 30 fps, but the EA demuxer assumes
> 15 by default.
> It appears the framerate is set with the use of the 0x1B code in the SCHl /
> PT00 header.
nice find
> I have made changes in the patch attached to fix these problems.
thx for sharing.
the patch needs a small amount of improvement. see below for my suggestions.
> From 306f9db010cf000eb8477aca243fc970f5b95df8 Mon Sep 17 00:00:00 2001
> From: aaron <aaronrules5alt at gmail.com>
> Date: Fri, 19 Jul 2024 07:30:10 -0400
> Subject: [PATCH 1/1] Mono ADPCM for EA WVE Files / Fix Framerate
>
> ---
> libavcodec/adpcm.c | 57 +++++++++++++++++++++++++-----------
> libavformat/electronicarts.c | 12 ++++++--
> 2 files changed, 50 insertions(+), 19 deletions(-)
>
> diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
> index f63afefd63..238214877d 100644
> --- a/libavcodec/adpcm.c
> +++ b/libavcodec/adpcm.c
> @@ -262,7 +262,7 @@ static av_cold int adpcm_decode_init(AVCodecContext * avctx)
> break;
> case AV_CODEC_ID_ADPCM_DTK:
> case AV_CODEC_ID_ADPCM_EA:
> - min_channels = 2;
> + min_channels = 1;
> break;
> case AV_CODEC_ID_ADPCM_AFC:
> case AV_CODEC_ID_ADPCM_EA_R1:
> @@ -914,10 +914,12 @@ static int get_nb_samples(AVCodecContext *avctx, GetByteContext *gb,
> bytestream2_seek(gb, -8, SEEK_CUR);
> break;
> case AV_CODEC_ID_ADPCM_EA:
> + /* Stereo is 30 bytes per block */
> + /* Mono is 15 bytes per block */
> has_coded_samples = 1;
> *coded_samples = bytestream2_get_le32(gb);
> *coded_samples -= *coded_samples % 28;
> - nb_samples = (buf_size - 12) / 30 * 28;
> + nb_samples = (buf_size - 12) / (ch == 2 ? 30 : 15) * 28;
> break;
> case AV_CODEC_ID_ADPCM_IMA_EA_EACS:
> has_coded_samples = 1;
> @@ -1652,10 +1654,10 @@ static int adpcm_decode_frame(AVCodecContext *avctx, AVFrame *frame,
> int coeff1l, coeff2l, coeff1r, coeff2r;
> int shift_left, shift_right;
>
> - /* Each EA ADPCM frame has a 12-byte header followed by 30-byte pieces,
> - each coding 28 stereo samples. */
> -
> - if (channels != 2)
> + /* Each EA ADPCM frame has a 12-byte header followed by 30-byte (stereo) or 15-byte (mono) pieces,
> + each coding 28 stereo/mono samples. */
> +
> + if (channels != 2 && channels != 1)
> return AVERROR_INVALIDDATA;
>
> current_left_sample = sign_extend(bytestream2_get_le16u(&gb), 16);
> @@ -1665,37 +1667,58 @@ static int adpcm_decode_frame(AVCodecContext *avctx, AVFrame *frame,
>
> for (int count1 = 0; count1 < nb_samples / 28; count1++) {
> int byte = bytestream2_get_byteu(&gb);
> - coeff1l = ea_adpcm_table[ byte >> 4 ];
> - coeff2l = ea_adpcm_table[(byte >> 4 ) + 4];
> + coeff1l = ea_adpcm_table[ byte >> 4 ];
> + coeff2l = ea_adpcm_table[(byte >> 4) + 4];
these whitespace-only changes shouldn't go in the patch.
> coeff1r = ea_adpcm_table[ byte & 0x0F];
> coeff2r = ea_adpcm_table[(byte & 0x0F) + 4];
>
> - byte = bytestream2_get_byteu(&gb);
> - shift_left = 20 - (byte >> 4);
> - shift_right = 20 - (byte & 0x0F);
> -
> - for (int count2 = 0; count2 < 28; count2++) {
> + if (channels == 2){
> + byte = bytestream2_get_byteu(&gb);
> + shift_left = 20 - (byte >> 4);
> + shift_right = 20 - (byte & 0x0F);
> + } else{
> + /* Mono packs the shift into the coefficient byte's lower nibble instead */
> + shift_left = 20 - (byte & 0x0F);
> + }
> +
> + for (int count2 = 0; count2 < ( channels == 2 ? 28 : 14); count2++) {
"count2 < ( channels..." looks out of place.
drop the space after the parenthesis.
> byte = bytestream2_get_byteu(&gb);
> next_left_sample = sign_extend(byte >> 4, 4) * (1 << shift_left);
> - next_right_sample = sign_extend(byte, 4) * (1 << shift_right);
> + next_right_sample = sign_extend(byte, 4) * (1 << shift_right);
>
> next_left_sample = (next_left_sample +
> (current_left_sample * coeff1l) +
> (previous_left_sample * coeff2l) + 0x80) >> 8;
> +
> next_right_sample = (next_right_sample +
> (current_right_sample * coeff1r) +
> (previous_right_sample * coeff2r) + 0x80) >> 8;
>
> previous_left_sample = current_left_sample;
> current_left_sample = av_clip_int16(next_left_sample);
> +
> previous_right_sample = current_right_sample;
> current_right_sample = av_clip_int16(next_right_sample);
> +
> *samples++ = current_left_sample;
> - *samples++ = current_right_sample;
> +
ditto for these whitespace-only changes above.
> + if (channels == 2){
> + *samples++ = current_right_sample;
> + } else {
> + next_left_sample = sign_extend(byte, 4) * (1 << shift_left);
> +
> + next_left_sample = (next_left_sample +
> + (current_left_sample * coeff1l) +
> + (previous_left_sample * coeff2l) + 0x80) >> 8;
> +
> + previous_left_sample = current_left_sample;
> + current_left_sample = av_clip_int16(next_left_sample);
> +
> + *samples++ = current_left_sample;
> + }
> }
> }
> -
> - bytestream2_skip(&gb, 2); // Skip terminating 0x0000
> + bytestream2_skip(&gb, channels == 2 ? 2 : 3); // Skip terminating NULs
> ) /* End of CASE */
> CASE(ADPCM_EA_MAXIS_XA,
> int coeff[2][2], shift[2];
i suggest splitting this into two patches, one for mono adpcm ea, another for
the frame rate fix.
> diff --git a/libavformat/electronicarts.c b/libavformat/electronicarts.c
> index f7f6fd4cab..c141a172dd 100644
> --- a/libavformat/electronicarts.c
> +++ b/libavformat/electronicarts.c
> @@ -86,6 +86,8 @@ typedef struct EaDemuxContext {
> enum AVCodecID audio_codec;
> int audio_stream_index;
>
> + int framerate;
> +
> int bytes;
> int sample_rate;
> int num_channels;
> @@ -198,6 +200,10 @@ static int process_audio_header_elements(AVFormatContext *s)
> av_log(s, AV_LOG_DEBUG, "end of header block reached\n");
> in_header = 0;
> break;
> + case 0x1B:
> + ea->framerate = read_arbitrary(pb);
> + av_log(s, AV_LOG_DEBUG, "Setting framerate to %u", ea->framerate);
> + break;
av_log trailing "\n" missing
> default:
> av_log(s, AV_LOG_DEBUG,
> "header element 0x%02x set to 0x%08"PRIx32"\n",
> @@ -367,6 +373,8 @@ static int process_ea_header(AVFormatContext *s)
> AVIOContext *pb = s->pb;
> int i;
>
> + ea->framerate = 15;
> +
> for (i = 0; i < 5 && (!ea->audio_codec || !ea->video.codec); i++) {
> uint64_t startpos = avio_tell(pb);
> int err = 0;
> @@ -427,12 +435,12 @@ static int process_ea_header(AVFormatContext *s)
> case pQGT_TAG:
> case TGQs_TAG:
> ea->video.codec = AV_CODEC_ID_TGQ;
> - ea->video.time_base = (AVRational) { 1, 15 };
> + ea->video.time_base = (AVRational) { 1, ea->framerate };
> break;
>
> case pIQT_TAG:
> ea->video.codec = AV_CODEC_ID_TQI;
> - ea->video.time_base = (AVRational) { 1, 15 };
> + ea->video.time_base = (AVRational) { 1, ea->framerate };
> break;
>
> case MADk_TAG:
> --
-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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